Another (paid) DLC called "Portugal Pack" to Civilization VI is now available for Linux on Steam!

This new content pack introduces João III as the leader of Portugal.

Includes the Portugal civilization with João III, the Nau unique unit, and two unique structures, the Navigation School building and the Feitoria.
Civ Unique Ability: Portugal’s unique ability, “Casa Da Índia,” significantly increases the yields of International Trade Routes, but limits those routes to cities on the coast or with a Harbor. This ability also grants Trader units additional range and the ability to embark on water tiles as soon as they’re unlocked.
Leader Unique Ability: Joao’s unique ability is “Porta Do Cerco,” which grants all units increased Sight. It also increases Trade Route capacity whenever Portugal meets a new civ and provides Open Borders with all city-states.
Unique Unit: Portugal’s unique unit, the Nau, is a naval melee unit that replaces the Caravel. It starts with one free Promotion, requires less maintenance than the Caravel, and has two charges to build Feitorias, special shipping ports unique to Portugal.
Unique Infrastructure: Portugal has access to two unique structures.
Portugal’s unique building, the Navigation School, replaces the University building and increases Production toward naval units in each city that builds it. It also increases a city’s Science yields for every two coastal or lake tiles within the city’s borders and grants additional Great Admiral points.
The Feitoria can only be built by a Nau unit on a foreign city’s coastal tile next to a luxury or bonus resource. Sending a Trade Route to a city with a Feitoria provides Portugal with additional Gold and Production.

New “Zombies Defense” Game Mode
The Portugal pack also introduces the new Zombies Defense game mode. In this optional game mode, the dead don’t stay dead for long and present an ever-growing threat to the world’s civilizations.
BRAINS!
The Dead Don’t Rest: Every unit has a chance to respawn as a ravenous Zombie when it dies. Zombie units hunger after and attack the nearest non-Zombie unit; any units they slay succumb to the infection and respawn as Zombies themselves.
The Living Fight Back: An arsenal of new trap and barricade improvements deal damage to hostile units that pass through or near them and can be built in owned or neutral territory. Zombies’ obsession with brain-banquets and digestive-devastation means they can only fall victim to these improvements and never pillage them.
Humanity Takes Control: Two new projects allow civilizations to temporarily subjugate Zombie units within a city’s limits, putting them under player control. The “Holy Site: Turn Undead” project unlocks early, but controls Zombies only briefly. The “Campus: Horde Control” project unlocks later in the game, but grants additional turns with which to command Zombies’ mindless mayhem. Meanwhile, the “Zombie Outbreak” spy operation attempts to spawn Zombies on worked tiles in another player’s city.

New map script and new World Wonders:
The Portugal content pack also includes a new map script and two new World Wonders:
Wetlands Map Script: Squelch your way to victory through a soggy map dominated by Marshes. This map offers new strategic challenges and defensive possibilities: while Marshes penalize Movement, careful positioning can allow ranged units to exploit enemies’ reduced speed.
Torre de Belém World Wonder: This imposing tower historically served as a ceremonial gateway to Lisbon in Portugal. Grants additional Gold and Great Admiral Points. International Trade Routes embarking from this city receive additional Gold for every Luxury Resource at the destination. When constructed, any cities owned by the civilization but located on other continents receive the cheapest building they can construct at that time.
Etemenanki World Wonder: The name of this Babylonian ziggurat translates to “temple of the foundation of heaven and earth.” It grants additional Science yields every turn, as well as bonus Science and Production to all Floodplains in the city that builds it and Marsh tiles in that civilization.

Also a huge update for the main game has been released:

Free Game Update
[BALANCE/POLISH]
General Updates
• Replace the old Lisbon City-State with the Mogadishu City-State
• Fixed an issue where Production was not being added to Holy Sites in captured cities when having the Work Ethic religious belief.
• Macedon's ability Hellenistic Fusion will now only trigger when a city is first conquered (it previously was triggering for districts built after the city was occupied).
• Fixed incorrect yield text for Cliffs of Dover in certain tooltips.
Babylon Pack
• Tourism from all Heroic Relics is now 6 (was 10)
• Fixed an issue where the Questing Knight’s combat strength would increase after the player advanced eras.
• Fixed an issue where a Hero could not be recalled with Faith when a Free City was recaptured.
• Fixed an issue where the Hero Mulan was able to attack land units while embarked.
Kublai Khan and Vietnam Pack
• Industry bonuses are now displayed on Product tooltips when creating a trade in the deal menu.
• Fixed an issue causing larger than intended Tourism rewards from monopolized resources.
• Fixed an issue where Products could be created from pillaged Corporations.
• Fixed an issue where the Corporation name would be missing when making a deal with the AI.
• Fixed an issue where Housing would not be displayed when placing the Preserve district.
• Fixed an issue where Corporation Product ownership was not always being properly assigned. If no custom name is used for a Corporation, a generic name will be used.

Barbarian Clans
• Sumeria's Unique Ability Epic Quest has been updated for Barbarian Clans gameplay: When you disperse a Barbarian Outpost, receive a Tribal Village reward in addition to the usual Experience Points. Pay half the usual cost to levy City-State units.
• Clan conversion info now appears in the Treat with Clan UI.
• Improved naval clan priority to focus on creating more naval units when located on small landmasses.
• A civilization that is currently selected as an Incite target will no longer appear on the Incite dropdown menu.
• Added tooltip info about City-State conversion disabled status on clan banner and in Treat with Clan UI.
• Fixed an issue where Barbarian bribe indications were remaining on unit flags after the bribe had expired.
• Fixed an issue where notification icon for the Bribe function would not display the correct icon.
• Fixed an issue where the ESC key would not close out the Treat the Clan UI.
• Fixed an issue where duplicate Civilizations would be indistinguishable on the Incite dropdown menu.
• Fixed an issue where hired units would sometimes spawn within the Barbarian Outpost.
• Fixed an issue where a defender unit would fail to spawn on a Barbarian Outpost during the Barbarian player’s turn after being raided.
• Fixed an issue where players could still use the Ransom function while having an insufficient amount of Gold.
• Fixed an issue where the map would recenter on the first clan on which a player action was used after interacting with other clans.
• [Multiplayer] Fixed an issue where the Barbarian Outpost banner would appear in the fog of war after another user had discovered them during a Hot Seat game.
• [Multiplayer] Fixed an issue where converted City-States would fail to declare war on players their Suzerain is currently at war with.
[AI]
• AI will make better use of cultists.
• AI’s value of tech will be limited by the number of units it can build.
[UI]
• Added new icons for the Leader Selection Pool to help differentiate pools.
• Added warning tooltips for choosing similar Civ jersey colors to single player Advanced Setup menu.
• [Base game] Fixed an issue where the player would not be able to trade Great Works or Relics in the deal menu.
• Fixed an issue where the “Replay Movie” button would no longer function when the player returned to the Victory/Defeat screen after viewing the History Timeline during gameplay.
• Fixed tooltip info showing per-turn resource info when adding a city with resources to a trade deal.
• Fixed an issue where leader quotes played from the Civilopedia would continue after the Civilopedia was closed.
• Fixed an issue where the city recommendation tooltip would appear when the player hovers over recommended Builder improvement icons that were on the same tile as the recommended settlement icon.
• Fixed an issue where an incorrect number of selected leaders will display when viewing the Leader Pool section of the Game Summary in a Multiplayer Staging Room.
• Various text fixes.
[MP]
• [Ethiopia Pack] Fixed an issue where Menelik would not be available for base game multiplayer scenarios.
• Fixed an issue that caused graphical corruption on the UI overlay after playing in Pirates multiplayer when loading a Single Player save.
[CRASHES]
• Fixed a crash caused by the delayed death of Spies.
• Fixed a crash that would sometimes occur when Barbarian Clans converted to City-States.
• Fixed various crashes.

[ALL]
• Fixed an issue where the highlight does not cycle when navigating jersey colors in Advanced Setup.
• Fixed text that was misaligned in the Select Natural Wonders menu.
• Fixed multiple locations throughout the game where the text would overrun.
• Fixed an issue where tooltips cannot be toggled for leader icons in the right tray in the Pirates Scenario.
• Fixed an issue where an incorrect tooltip is present on the Previously Recruited tab when attempting to purchase with faith in the Heroes and Great People menu.
• Fixed an issue where the text alignment of “Game Random Seed” and “Map Random Seed” was offset in the Advanced Setup menu.
• Fixed an issue where the HUD Ribbon does not open correctly for players in Hot Seat games if a player changes the Show Yields in HUD Ribbon option during the game.
• Fixed multiple locations where text would overlap other items.
• Fixed instances where text and icons could appear small in various game locations.
• Fixed an issue where the "Created By" text on the Heroic Relic pop-up displays as "Created By Tribal Villages" in certain languages during a Heroes and Legends game.
[PS4 & XB1]
• Fixed an overlapping issue with the Gossip menu in Russian.
• Fixed an issue where the title "American Empire: Teddy Roosevelt (Rough Rider)" overlapped the scroll bar on the Leader loading screen in Polish.
• Fixed the titles for the "The Mask of Bahophet" and "Voice of Aiwass" achievements.
• Fixed an issue where a close button prompt could be present on the World Rankings menu and the Treat with Tribe menu in Rise & Fall and Standard games.
• Fixed an issue where the background stretches beyond the top edge of the Great Works menu.
[SWITCH]
• Fixed an issue where the text “CREW” overlapped the left thumb stick button icon in the unit panel in the Pirates Scenario.
[XB1]
• Fixed an issue where the Client does not join the Host when accepting an invite during the Ready Up Countdown in a Multiplayer lobby.
• Fixed an issue where the term 'DLC' was present before certain downloadable content in non-English localizations on the Manage Game & Add-ons menu on Xbox.
• Fixed an issue where the host hangs indefinitely after the client disconnects the LAN cable while pressing the "Ready to Join" button in the Multiplayer Staging Room on Xbox.
• Fixed an issue where Gamer cards cannot be accessed when selecting gamertags on the Trade Posts section of the City Details menu.
• Fixed various crash issues that could occur during gameplay or game setup.
[PS4]
• Fixed a crash that could occur when retiring.