`ClassVar` cannot contain `Self` type in generic classes

This rule seems correct when Self appears in a covariant position, like

class MyGeneric[T]:
    # ill-defined, what's the type of MySequence.example?
    example: ClassVar[Self]  # error: ClassVar cannot contain Self type in generic classes

However, if Self appears in a contravariant position, I do not see why this should be an error.

class MyGeneric[T]:
    pre_method_hooks: ClassVar[list[ Callable[[Self], None] ]] = []

Full example: https://mypy-play.net/?mypy=master&python=3.12&gist=951d5b3a168378cd33d9fc4aebd4572e

from typing import Callable, ClassVar, Self, Any
from abc import abstractmethod

class Transform[X, Y]:
    pre_transform_hooks: ClassVar[list[Callable[[Self], None]]] = []  # ❌️

    def __init_subclass__(cls) -> None:
        super().__init_subclass__()
        original_transform = cls.transform

        def wrapped_transform(self: Self, x: X, /, *args: Any, **kwargs: Any) -> Y:
            for hook in cls.pre_transform_hooks:
                hook(self)
            return original_transform(self, x, *args, **kwargs)
        cls.transform = wrapped_transform  # type: ignore[method-assign]

    @abstractmethod
    def transform(self, x: X, /) -> Y: ...

class Demo(Transform[int, int]):
    def transform(self, x: int, /) -> int: return 0

    def hello_world(self) -> None:
        print(f"Hello, world! from {self}")

    pre_transform_hooks: ClassVar[list[Callable]] = [hello_world]

Demo().transform(0)  # prints "Hello, world! from <__main__.Demo object at ...>"

main.py:5: error: ClassVar cannot contain Self type in generic classes  [misc]
Found 1 error in 1 file (checked 1 source file)

Reproduce the diagnostic using the linked mypy-play example or the shown main.py snippet, then trace the ClassVar and Self validation that rejects the generic class member. Compare the covariant and contravariant cases and check existing tests for this rule. Done means the intended contravariant case is handled consistently while the invalid covariant case remains diagnosed.