> Here the error message is about "positional arguments," which are
> different from parameters.

Okay.  So is it also planned to change the existing error messages for user-defined functions?  E.g.:

>>> def f(a, b=1):
...     pass
... 
>>> f()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: f() missing 1 required positional argument: 'a'


If yes, then I think all these changes need to be coordinated, and that probably involves submitting a proposal to the mailing list.  If no, then I think the change proposed in this issue is not an improvement, since it makes the error messages overall inconsistent.