[Typing-sig] PEP 585

Hello, after being told in issue 38756 of the python bug tracker that PEP 585 will add generic typing to many standard collections/containers I looked at which types will get generic versions. I noticed that collections from weakref were not included (WeakDictionary, WeakSet etc). WeakKeyDictionary and WeakValueDictionary should probably automatically be generic as they extend _collections_abc.MutableMapping but WeakSet does not. Would it be possible to clarify that WeakDictionaries or subclasses in general will become generic but more importantly I think it should be worth considering add WeakSet to the PEP I would like to hear your thoughts on this topic... Greetings Nils Kattenbeck