From a could/might review, a suggestion by @zygoloid regarding [class.copy.assign]p8:

assignment operator with a parameter type that could/can be that of a

I don't like the old or new words here. I think we should rephrase this whole sentence.

I also wonder if this is actually a normative rule at all, or if this is a consequence of the rule in [class.copy.assign] talking about "explicitly declar[ing] a copy assignment operator". If it's a consequence, then it should be a note, and if not, then it shouldn't be phrased as "this happens because the declaration is not considered an explicit declaration of the operator" but instead as something like:

A using-declaration that brings in an assignment operator from a base class never suppresses the implicit declaration of an assignment operator of the derived class, even if the base class assignment operator, when considered as a member of the derived class, is a copy assignment operator or a move assignment operator ([class.copy.assign]).

I think this is repairable editorially, but not by a one-word change.