Would be great if they could do that for Mac as well, although Metal is a deadend (for game devs) so they may not bother. I have had some decent success running wine games on Mac.
On the proton github repo there are instructions for building for Mac and moltenvk libraries. It’s probably not as mature as the Linux version but there are bits hinting here and there. Link: https://github.com/ValveSoftware/Proton