From a runtime type inspection perspective I'm avoidant of scoping rules being introduced that would case accessing type variable outside that scope to be an error. As a simple example,
class Foo(Generic[T]): value: T
type_hints = get_type_hints(Foo)
currently returns {"value": T}. Several libraries do want to access a type variable being there outside of the class. It can be useful for documentation generation, serialization code based on types, or runtime validation checks. T needs to not be deleted I think for this to work.
A more niche case I'd like to have some working equivalent is,
class Foo(Generic[T]): value: T
Foo.__orig_bases__
currently gives Generic[T]. Some way of getting the type variables that class is parameterized by would be nice to have. This one I'm more ok if exact code needs to change given __orig_bases__ is minimally documented as long as information stays inspectable.
auto_variance would be nice to have utility function in standard library/typing inspect to identify which variance each type variable has at runtime. This is minor though. I think runtime variance usage is rather rare.