When I review itch games I always advocate for native Linux support. If the devs see it, they will do it. The ones I talk to who haven't don't want to put in the effort to learn how to compile it for Linux if barely anyone would use the port.
It's rough. I think for it to make an impact on the twitch side of things, the streamer would need to be the one to make the stand. Afterall, your subs are already paid for; nothing more you could really do other than avoid the site for a week.
That'll be a big one. I could see tons of artists wanting to flock to a platform without risks of a ban.