Type Variable Specialized by Generic

It seems that Type[...] variables dont specialize correctly:

Types = Union[int, str]
T = TypeVar('T', bound=Types)

class A:
    x: Types
    y: Type[Types]

class B(A, Generic[T]):
    x: T        # ok
    y: Type[T]  # error: Incompatible types in assignment

The error that arises is

error: Incompatible types in assignment (expression has type "Type[T]", base class "A" defined the type as "Union[Type[int], Type[str]]")

I believe this is a bug and it should be an allowed specialization (similar to the instance x above), unless there is a counterexample I'm not thinking of?

Tested with mypy v0.660 as well as mypy master + typed-ast master, CPython 3.7.1

Use the supplied Python snippet as the reproducer and inspect the type-checking path for generic attribute overrides involving Type[T] and Union bounds. Done means mypy accepts y: Type[T] in B without the incompatible-assignment error, with a regression check for this example.