Post I'm referring to: What are the differences between credential stuffing and password spraying? I don't recall seeing mods move short discussions from answer comments to chat before. Usually this moderation action is reserved for people having a very long back and forth discussion, and even that is fairly rare.
In my opinion, moving comments to chat should be reserved for extreme situations since most users won't be likely to follow the link, and thus will miss out on the information they provide. While I understand some people believe that "comments are not for anything permanent", the de facto practice on the site has been to preserve them.