At this point, we should switch to Python 3.9 (dropping any dependencies which are not ready) and then mypy should accept the syntax without the future import.

That would probably fail some of the checks as some files could rely on that dependency.

I suggest a phased approach for Python 3.9 migration and mypy error fixes:

1. Retain Python 3.8+ compatibility first: Keep using  typing.List  instead of native  list[type]  for now, since CI doesn’t support 3.9 yet due to dependency issues. This fixes the mypy errors and keeps the codebase stable.
​
2. Prepare for 3.9 migration: Document all places using  typing.List  and create a task to switch to native type hints once dependencies are updated.
​
3. Handle  future import annotations : This import is useful for Python 3.7+ type hinting, so keep it—resolve mypy’s dissatisfaction by adding the relevant ignore comments or updating the mypy config file.