Not sure why this would happen when Valve doesn't need any extra money from the markets, and is privately owned. Gabe owns >50%, rest is apparently Valve's employees and execs. Gabe is divorced, has two sons, so I suppose that 50% goes to those guys. So I guess it depends how much the brothers think they need cash.
@Custoslibera
I think Robin Walker would be a fantastic successor.
https://en.m.wikipedia.org/wiki/Robin_Walker_(game_designer)
Interesting, have not heard of them before but could be a contender.
Valve is a company whose profit model is based on DRM. They were never your friend. Thanks for proton, though.
I hope they keep with Linux...