We only officially support VRChat on Steam Deck’s SteamOS, which is a flavor of Arch.
You should be able to get VRChat working on any distro as long as you’re running Steam, and run VRChat through Proton. I usually use the latest experimental build of Proton (check the compatibility settings in properties) and that works fine, although there’s a few weird things here or there.
EAC works under Linux as long as you’re running through Proton.