Does anyone play any gamepass games on Fedora Silverblue?
Steam is relatively established, but with my console subscription I am entitled to play their PC games too and I want to play Age of Empires 4.
I cant see any guides aimed at silverblue (or non steam in general) for this game.
AOE 4 is a windows game so with ProtonGE Custom you can play Age of Empires IV easily in Steam. You can check the latest reports below:
https://www.protondb.com/app/1466860
When it comes to Gamepass, unfortunately you can’t play this game because there is no official version of Linux version of Gamepass App. Will it work with Wine in the future I am not sure we will see it 
In general best way to play games in Silverblue and Kinoite is Steam with the help of proton for Windows games. Also what other options you have? Play from GOG, itch.io [Steam much better], native linux games, use wine to play some Windows games and finally emulators.
On Steam I will have to buy it.
On gamepass I get it for free as part of my xbox gamepass ultimate subscription.
Does the gamepass include cloud gaming? If so, you might be able to play using a browser.