[the8472]

No, that's not obvious at all. A single event is evidence that some abuse still happens, it does not tell us how much more abuse there would be in the counterfactual where the history wasn't available.

discourage != prevent all

[ktm5j]

I get what you're saying, but I feel like they should highlight comments in some way if a repo admin completely replaces a comment with different text. I'm struggling to imagine a situation where that would really be appropriate. The "Edited by: username" seems too easy to overlook.

[the8472]

They could show multiple post authors, similar to how they do for co-authored commits.