That'll be really helpful for nested method calls which proxy a lot of their arguments along. I can also see that helping out when creating stub libraries.
(I don’t know about others, but it was obvious to me from the start that the way the *args and **kwargs type annotations refer to the sequence values rather than the args/kwargs bindings was always going to cause confusion, and was very likely to cause problems down the line when they wanted more precise typing; and that day has arrived for kwargs, no idea if they have any plans for similar on args, which is sometimes useful. They should just have required `*args: List[T], **kwargs: Dict[str, T]` from the start.)