They could use an LLM to parse through the version history of all those posts/comments, to use it to train another LLM with it. It sounds like a bad (and expensive, processing time-wise) idea, but it could be done.

EDIT: thinking further on this, it's actually fairly doable. It's generally a bad idea to feed the output of an LLM into another, but in this case you're simply using it to pick one among multiple versions of a post/comment made by a human being.

It's still worth to scorch the earth though, so other human users don't bother with the platform.