It will never happen, but my dream is for the Asahi devs, Valve, and Apple to all get together to build out a cross-platform Proton to emulate and play games built for Windows on both x86 and ARM hardware running Linux.
A Steam Deck with the performance and power efficiency of an M-series ARM chip and the entire library of games that run on Proton is just...dreamy.
The end game for Valve isn't Steam Deck 2 or 3 (which is statistically impossible for Valve to produce), but for Steam to be on everything.
Most of the studios that own those games, and target POSIX like OSes on mobile phones and game consoles, are yet to bother with GNU/Linux versions for SteamOS.
What Valve want is the dissolution between platform/architecture and store. By my eye, it's the driving force of their efforts, more so than them selling hardware or being the open source good guys. Not to undervalue their work in helping make Linux a first class citizen for gaming, but the core of their business model is getting people to engage with their store, full stop, and being able to sell their games on Android (and elsewhere) would massively extend their reach.
This may go both ways too, there's also been indications that Valve have been tinkering with Waydroid, meaning Steam could also become a store for Android-native games.