I'd be willing to bet the javascript trash forum that we're supposedly migrating to won't allow that feature without months of changes. Pretty sure you could just add a query to the existing forum to check the age of the most recent post, and if it's greater than several months; disallow the post. SMF probably wouldn't be that hard to extend.
Hmm, is it that hard to take a look when the first post was posted? I am aware many people here just jump to the last post(+/-s) and don't bother to check the date but this is in the first place their fault and I reported them several times in the press section.
I saw it was from like 2014 or something, but wasn't
too long ago in the grand scheme of things. Also, the forum isn't a live-only-thing, not just "guys, it's older than 10 min old, forget it!!!"
Personally, I used to report every bumped topic older than 3 months. I don't see why should a discussion be made after such long period.
If an old topic contains genuine information and is very important to the community then it is ok. Other topics have to be used as a reference in a new topic (season 2 somehow).