Also: there were lots of independent projects to remove the GIL/speed up Python: from Google, Dropbox, and others.
But due to the leadership/community model/aversion to big changes (except for alienating people with 2 to 3 changes) none of this was in the context of CPython, they were independent versions, that never caught on, and didn't leave anything (or much) behind to the regular CPython when they folded.