Wine is not an emulator, and has nothing to do with projects as Yuzu, Dolphin, PCSX2 and others.
(if running out on ARM, there is still ARM to x86 emulation but that is just generic ARM to x86 emulation which has not that much to do with Yuzo per se)
Wine/Proton is a community implementation of the Windows APIs for Linux, it uses no Microsoft code nor needs any. It runs binaries that Valve already has permission to distribute (the games).
Lolol
other games are only as much of interest as it might be games which could end up on steam or games which show some issue with the emulation which could be used to improve proton
there is also the thing that proton or wine just barely count as emulation, they are a bit of emulation but mostly just providing compatible OS interfaces adaption (through Yuzu might but be that much different given how "mainstream" (but old) the switch hardware is)