I think forums should generally let new discussions happen even on repeated topics. When you lock threads just because "we already talked about this," you kill the community vibe.

Tech and crypto change so fast - last year's Bitcoin discussion is already outdated. Plus, new members bring fresh perspectives that would be lost if we always redirected to old threads.
Instead of shutting conversations down, maybe just link to previous discussions while letting the new one continue. This gives context without stifling engagement.
The best forums feel alive with conversation. A bit of topic overlap is worth it if it keeps people talking and sharing ideas. After all, forums are about community, not just being a perfect archive.