Maybe. But the 5000 day retention most servers have is since upload. It doesn't relate to how old the series or movie in question is. If you search for a title, you're almost certainly going to find a few dozen or so versions of that title in various definitions and age. For example, just for kicks, I searched for episodes of the Andy Griffith show, and the oldest files I found were 3700 days old. The series is a bit older than that, of course.

You can get plenty of older shows on Usenet it's not like you won't find something like Star Trek from the 60's. Hell I recently started downloading V from 1984 so...