Lots of games won't ever be converted to Wayland (maybe some unofficially by replacing libraries with updated ones that still work with the game), we'll need some nested X server like xwayland in rootful mode once wayland compositors remove their xwm.
Reached? Win32 has been the most stable userspace ABI for Linux for more than a decade (or even 2?). Wine is a really old project and Win32 API / ABI has always been stable. The implementation of the API / ABI was very patchy earlier but the functions that defines the ABI has always been there, their signature and calling conventions are stable.
