And GNU Emacs has to fork, absent getting RMS's buy-in, which is now not the way to bet. That's where the serious fork has to occur, I presume it could get by with LLVM output, right? Which of course would not be ideal if you're using GCC in your project....

Oh, if only they'd ignore the heathen fork of one of their marque projects. Not going to happen with EMACS, 99+% of its greatness is due to RMS by universal acclimation as of the very early '80s.