I created PR 28116 to deprecate the lib2to3 package: replace PendingDeprecationWarning to DeprecationWarning.
In 2021, I don't think that we should keep the 2to3 tool in the stdlib. Python 2 reached end of line 1 year ago.
For the lib2to3 *parser*, IMO it would be better to maintain it outside the stdlib, and collaborate with other existing forks, like the parser used by Black.
The change is only about *deprecating* lib2to3, not *remove* it. For the removal, we should check if major projects which used it moved to something else.
It's kind of a shame that Python stdlib (lib2to3) cannot parse valid Python 3.10 code :-( IMO it's better to deprecate (and then remove) lib2to3.