Feb. 2, 2021
9:38 p.m.
I've put an updated version on Discourse: https://discuss.python.org/t/pre-pep-maintaining-the-stable-abi/6986 (and https://github.com/encukou/abi3/blob/main/PEP.rst is also up to date.)
I plan to turn it into a PEP next week.