But that’s not the problem.
The problem is that the questions are old.
It’s better to have the same question in a new era. The version info should be in the question. The question has either been answered or not, but it’s not relevant anymore for the original poster.
Only if it really is, you could add a new major version to it to indicate compatibility
I'm not sure I see the distinction. I've needed help doing "X", I googled "how to do X", and found ancient stackoverflow questions. The page has recent answers ranked the highest saying things like: "in recent years you should use the Y feature to do X". I haven't seen anyone get upset that the Y feature didn't exist when the question was posted.
Questions are often timeless. The answers change and SO shows them all with their timestamps ordered by its best guess at which will help you, the reader, not the original poster.
It’s better to have the same question in a new era. The version info should be in the question. The question has either been answered or not, but it’s not relevant anymore for the original poster.
Only if it really is, you could add a new major version to it to indicate compatibility