And no, the undeprecation wasn't because of Python 2 (Py2 doesn't have getfullargspec() - it's a Py3 only API).

The undeprecation was because there are a lot of 3rd party projects for whom the getfullargspec() representation is good enough, and switching to inspect.Signature instead requires a significant rewrite vs just wrapping inspect.Signature to produce getfullargspec() style output.

So getfullargspec() doesn't need to change at all for PEP 570 and should instead keep handling positional only arguments the same way it has since it was switched over to being based on inspect.Signature: reporting them the same way as positional-or-keyword parameters.