#17853 was in the context of metaclasses. Even so, I am puzzled by the opening statement there that

from enum import Enum  # I added this as necessary
class Season(Enum):
    SPRING = Season()

"works beautifully" at top level as it indeed raises
NameError: name 'Season' is not defined

My point here is that changing the output of

n=1
def f(n=2):
    class A: n=n
    return A
print(f().n)

from 1, as it has been from the beginning (except for the print change) to 2, which I believe is implied in the request, is not the sort of syntax change we do. Hence I think this should be closed.