Well that's not how it actually works in practice, is it? Look, for instance, at The Clinic and its many, many, "many months (or years) old" threads that come back to life when new content comes along. Please don't suggest that such threads have to be killed and reborn with linkbacks, cause that's just *** up and defeats the intended purpose of many of these threads.
The forum rules apply everywhere on the forums, but the categories like Off Topic or the Clinic aren't as time sensitive as other spots. I don't suspect this will turn into a major issue for those specific subforums, but if it does become a problem we'll figure out the best path forward.