The new version on the Steam Deck isn’t available - the old version of course is, but you might as well use Bazzite.

I dont think Valve would bother trying to convert people to Linux - regardless of where people’s OSes are, they are the gaming store. Plus, Valve really doesn’t think developers should develop Linux native ports, so I dont think they’re really push people to use Linux - just use whatever you want and play shit with Proton if needed.