I wish Slack had a feature to "threadify" comments that have already been made. I wouldn't even mind if Slack channels could designate certain users as "thread czars" that had the ability to move other users comments into a thread.
Sometimes replies bucket up under the thread, sometimes they do not. Sometimes what should be threaded get fragmented into separate threads.
Love this idea.
Some of the old school IRC-channel ops functions could go a long way too (I think discord is more like that).