Everything you need to know about Sid Meier's Civilization® VII, including answers to all your frequently asked questions!
As per the linked FAQ,
What platforms will Sid Meier's Civilization VII be available on?
Sid Meier's Civilization VII will be available on PS5, PS4, Xbox Series X|S, Xbox One, Nintendo Switch, and PC via Steam (which also supports Mac and Linux) and the Epic Games Store.
The Steam store (preorder) listing shows all three platform icons so I’m guessing they’re not just talking about making it work with Proton.
No mention yet of Aspyr (who ported Civ 5 & 6) as far as I can see.
Seems pretty clear to me: “We’re also releasing Civilization VII for MacOS and Linux / SteamOS” doesn’t just not mention Proton, there also isn’t a Proton on MacOS Steam. And you don’t get Linux and Mac system sepcs and platform icons on Windows-only games on Steam whether or not you can run them with Proton; you get ”Steam Deck Verified”.
(I’m half expecting them to walk that back later but for now the message seems clear.)