User blog comment:DaNASCAT/Introducing New Moderator Opportunities For Community Administration/@comment-1738746-20160116043732/@comment-5558012-20160117141020

I can't speak for 452, but I saw that as an example.

Overall, I operate under a leave-it-alone policy and don't over-moderate by closing old forum threads. The only reasons to close a thread are if it begins to become off-topic to a point where other moderation techniques can't handle it, if it's a duplicate thread (in which the other thread should be linked to in the reason), or if it's a closed topic that wouldn't benefit in any way by future comments (such as on communities that might use the forums to hold votes and the like). By not closing old threads (in addition to clear policy and enforcement), you can actually encourage a more organized forum by reducing the number of threads and increasing the likelihood someone will find the relevant thread they are looking for. We want people to add their unique opinions on a thread regardless of whether it's a day old or three years old, as long as it's relevant and adds to the discussion.

To go off one of your original points, I would love it if closed and highlighted threads were marked on the boards they are found on.