> I'm a bit surprised that this topic is brought up just days before the feature freeze of Python 3.10.

I have not idea about the technical details, but I think there is a bit of a discomment in the community:

Annotations have been around for years.

More recently, there was an official specification of how to use them for type hinting (was that PEP 484? a bit confused as that appears to still be provisional -- but anyway)

Since the specification for type hinting, a lot of work has been done on/with static type checkers (e.g. MyPy).

That work has informed the changes / improvements / proposals to the annotation and type system in Python.

However, those of us that are not actively involved (and maybe not that interested) in static typing have been not paying a great deal of attention to those efforts.

But some of us may, in fact, be using annotations for other reasons, but since we haven't been involved in the discussion, some issues may have been missed.

-CHB