I don’t think Valve would help implement something like that. They’ve shown a lot of initiative in trying to push Linux into the mainstream for gaming, and a move like that would be counterproductive to that goal.

Plus, it ignores the fact that the Deck isn’t trying to be the only piece of hardware in the space, just the first to prove it’s commercially viable, and they succeeded in that. Competitive devices are coming to market, and when gamers start buying them, it’s going to seem foolish to whitelist JUST the Deck.

Rockstar’s only semi-viable play of that nature is to attempt to require SteamOS as your Linux distro, but I see no way to do that so you always and only block other Linux distros.