>>2
On very slow boards, old threads used to get marked for deletion after a week or more of being around. This was around 2006-2007 or so.
I have no idea when it got removed, but I do know that threads on /jp/ can even last 2+ weeks if kept alive (bumped, but lower than 300 posts, otherwise bump limit is hit, and the thread can't be bumped anymore), which would mean that the "feature" got removed.
I think
>>1 is trying to making a bad joke about
/prog/ being old, but that's hardly an issue: many Usenet groups are over 30 years old and still alive and active, and
/prog/ is hardly that old.