It might be worth considering also updating ContextManager and AsyncContextManager to match what I did in python/typeshed#11048 for AbstractContextManager and AbstractAsyncContextManager, now that you've laid the necessary groundwork for defaults in _SpecialGenericAlias.

But we can also save it for a follow-up PR, if you'd prefer that. A change in typeshed doesn't make sense until we test 3.13 to the CI.

@Daverball Possibly, but note that we're one day away from the feature freeze for Python 3.13. I can spend some time on it later today, but please open a separate issue first.

@AlexWaygood if you have time, could you review this PR that just adds defaults for Generator and AsyncGenerator?

typing.Generator and typing.AsyncGenerator are deprecated, why are they getting new features?

typing.Generator and typing.AsyncGenerator are deprecated, why are they getting new features?

I would hope this isn't a real blocker here. From a user standpoint, users are told collections.abc variants are meant to behave identically. (they are actually documented as a deprecated alias and not as a separate object)

Deprecated alias to collections.abc.Generator.

(https://docs.python.org/3/library/typing.html#typing.Generator)

If this deprecation results in them not being equivalent anymore, you've broken the documented idea of them being equivalent.