Civlization 6 developer Firaxis is still working on those promises.
Civilization 6 was supposed to get mod tools and Steam Workshop support sometime after launch, but they have not yet arrived and nobody’s talking about them.
Until now, obviously, as I assume you realise if you’ve read the headline. In a recent Civilization 6 multiplayer stream, Firaxis’s Pete Murray said the developer is working on mod tools and Steam Workshop support right now, and that more information is coming just as soon as may be.
Although Civilization 6 modders have already produced some interesting work, official mod tools will make the scene far more accessible, and Steam Workshop support will make it much easier to find and install mods.
Cvilization 6 was one of the best-selling games on Steam last year, and seems to have chewed up all our TBS friends just like the last two did. See you in 1,200 hours, pals.