I work with different versions of Python3 (and 2 unfortunately) and some code is still in 3.6, hence I used OrderedDicts.
He thought that one cycle of "no ordering assumptions" would give a smoother transition. All 3.6 implementations would have dict ordering, but it was safer to not have people rely on it right away.
jython never released a P3 version so is irrelevant, ironpython has yet to progress beyond 3.4 so is also irrelevant.
It's also been frustrating with the lack of tooling support. I mean, I get it – it's hideously EOL'd – but I can't use Poetry, uv, pytest... at least it still has type hints.