I once asked if we can auto close threads after they were inactive for some time. To this day my biggest, and most necroed thread. 
People convinced me that threads should never get locked because there might always be something new and important to add. I kinda agree (but would love if the forum would auto tag every thread with the current patch number when it is created).
But now we have threads quite often where people don’t agree with OP and start an interesting discussion and by the time I would like to take part in that discussion it’s already over. That’s not how a forum should work. Forums are for discussion and as long as the discussion is civil it shouldn’t be stopped.