Incorrect has-type on unpacking of known TypeVarTuple type from classmethod from class with contrained generic #21693

Bug Report

When trying to unpack a tuple of a TypeVarTuple from a class method where that class contains a constrained TypeVar different from the one inhabited by the TypeVarTuple, mypy will issue a has-type error despite reveal_type showing the full correct type.

To Reproduce

https://mypy-play.net/?mypy=master&python=3.14&gist=856510a8671b57985553a6439ee673dc

class Container[T, P: (Literal[True], Literal[False])]:
    def foo(self) -> T:
        raise NotImplementedError

def f[*Ts, P: (Literal[True], Literal[False])](
    container: Container[tuple[*Ts], P],
) -> None:
    result = container.foo()
    reveal_type(result)  # Revealed type is "tuple[*Ts]"
    y = (*result,)  # Cannot determine type of "result"  [has-type]
    # Expected: tuple[*Ts]
    # Actual: tuple[Any, ...]
    reveal_type(y)

Expected Behavior

This code should have no errors, and the type of y should be tuple[*Ts]

Actual Behavior

Despite the reveal_type of result clearly showing tuple[*Ts], mypy issues a has-type error when unpacking it, and the resulting type of y ends up being wrong.

Additional Notes

If you remove the P generic, or make it normal/bound instead of constrained, the code works as expected.

Adding an annotation to result does get rid of the error, however in my actual code the result from foo is a tuple that I unpack like this result, index = container.foo(), so I cannot easily add that annotation. (I can like this result: tuple[*Ts] before the unpacking assignment, but that makes the code uglier.)

Your Environment

• Mypy version used: Playground 2.1.0 / master
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.14