I’ve hit the merge button on that PR now. If the rendered version of the PEP has pictures showing example timelines and support period overlaps, then it’s showing the version of the proposal I’m referring to in the quote above 
Relative to the version originally posted at the start of this thread, the substantive change is the one to actively encourage the publication of pre-built binary wheels for a release series as soon as the first pre-release is made available. That change in turn led to the reintroduction of routine alpha releases, specifically to mark pre-releases that include breaking changes in the full CPython C ABI.
The rest of the changes in the update are editorial ones that aim to make the PEP easier to read (adding pictures similar to those in PEP 602, presenting the example timeline earlier in the text, reducing the length of the abstract, etc).
(Note: the in-thread proposal has been updated to match the most recently published version, with a pointer down to this comment to indicate which parts of the thread related to the older version. With a mailing list, I would have just started a new thread for the new version, but that doesn’t seem likely to work as well on a web forum, since old topics don’t decay as quickly).