With a final generic class P, we don't currently allow the class P itself to be assignable to the type type[P]:

from typing import final 

@final
class P[T]:
    x: T

def expects_type_p(x: type[P]):
    pass

expects_type_p(P)  # this call currently fails but should succeed

Without the @final, this works, because we do implement this assignability to subclass-of types. But for a final class we simplify the subclass-of type to a simple GenericAlias type, and we don't implement assignability of an unspecialized ClassLiteral to a default-specialized GenericAlias type.