It's tough to say. Annoying Linux people like me tend to have horse-blinders on towards the rest of the world (hence the constant meme of the "Year of the Linux Desktop"), so it's tough for me to speculate with any kind of objectivity.

That said, Steam Decks seem to be selling pretty well, and people don't seem to mind the SteamOS part of it. I think that there's a chance that Linux will be a permanent fixture for Valve now. I don't think they're going to overtake Microsoft, but I think that "Steam Deck" is a viable enough of a target platform for game studios to develop against that it's here to stay.