Attribute access off a protocol's type shouldn't have a known type

Author: Enegg

peps/pep-0767.rst

@@ -498,7 +498,8 @@ This has a few subtyping implications. Borrowing from :pep:`705#inheritance`:
     has_name = NamedDescriptor()
 
   Type checkers should not assume that access to a protocol's read-only attributes
-  is supported by the protocol's type (``type[HasName]``).
+  is supported by the protocol's type (``type[HasName]``). Even if the attribute
+  exists on the protocol's type, no assumptions should be made about its type.
 
   Accurately modeling the behavior and type of ``type[HasName].name`` is difficult,
   therefore it was left out from this PEP to reduce its complexity;