Cleaned up:
Proposed optional feature: when a reply gets far more likes than the post it's replying to, promote that reply to its own top-level thread.
Dictation turned "the reply" into "the replies," but I read it as the one popular reply getting promoted.
Things to decide: what "many more" means (a ratio like 5x, a minimum like 10 likes, or both), whether the reply moves or stays in the old thread with a copy on top, whether the new thread links back to its parent, and who turns it on, since you called it optional.