Just slightly off topic (sorry Brett), but I have past experience with
the effort to try and sync the release cycle of something significant
with that of major distros - and it's just too hard. (What are major
"the major distros" anyway? the enterprise ones are on a completely
different cycle, and some have gone to rolling releases where there's
really nothing to sync to). By all means, if it hurts nothing to go for
a sync now, to take advantage of some synergies, great, but don't try
enshrine it in a PEP as a requirement going forward, there will only be
lots of pain as things start to skew. And they will.
This was actually one of the benefits of PEP 602: while Ubuntu LTS and Debian being offset means that every Python version is likely to find its way into one long lived Linux distro or another, the 12 month cadence means that when cycles don't line up well enough for immediate adoption, even the previous version should still be less than 18 months old (e.g. if Debian 11 were to ship Python 3.8 early in 2021 instead of 3.9).
The balance between alpha/beta/rc is definitely negotiable though, and I expect we'll see iteration on that aspect over the first few years.