I would agree that preserving the comment and replacing the author with “anon472844” for example (unzappable btw), is probably a much more useful solution.
This is a reasonable compromise, I think. If you wanted to make it even "better" you could use Llama to paraphrase the post to remove distinctive styling features.
I would like to point out that unfortunately the ephemerality of our face to face conversations is lost on the internet.
This is the heart of it. I absolutely understand the desire to have ephemeral conversations -- they're so important! Our lives would be so much worse without them! But the internet has different affordances and we shouldn't find a realistic way to inhabit them instead of pretending they don't exist.