Then again games didn't stop Apple from dropping x86-32 support, which nuked half of the Mac Steam library. It wouldn't be out of character for them to drop x86-64 support and nuke the rest which haven't been updated to native ARM.
Btw, Rosetta 2 actually supports x86-32. Which means you can run 32-bit Windows binaries through WINE, just not Mac 32-bit binaries.
So if you kill support for an old game, it will probably never be updated since it's no longer commercially relevant. Publishers are probably almost happy when old games get broken since they can sell you newer ones easier.
So even if they have kept the old OpenGL version that they had, many newer OpenGL-based applications cannot run on MacOS.
Since OpenGL is no longer evolving, it would not have been a great effort to bring the OpenGL support to the last version, and only then freeze it.