Although I'm curious about how they might address the "clickbait" issue of people having a massively upvoted/boosted post, and then changing the post to say something else entirely.

That seems like it might be a problem if people are allowed to edit titles.

*Title edited small text could be added maybe
Editing titles much later can be useful for example when discussing news or findings that later get disproved, at which point one could edit the title to reflect that so that future readers don't risk going down the path of trusting it.
Tag with "Title edited" also include a button showing former title as an uncoverable element.