I had an epiphany as I lay in bed last night. I realized that when I posted my thread a “block” popped up that said “your topic is similar to” and showed several very old threads with links.
Could it be that the reason so many old threads are suddenly popping up by new posters is because that link is encouraging people to drag up old threads? Could the root cause be that algorithm? I urge the cyberfolks to consider shutting that function off. Perhaps then old threads will stop popping up.