I deleted all my comments on Reddit earlier in the week. Reddit have undeleted them!
I'm not alone, others have seen this. https://www.reddit.com/r/RedditAlternatives/comments/14agh7d/reddit_starting_to_bring_back_deleted_comments/

Edit: It's possible that the deletion only worked on public posts, it seems?

Reddit starting to bring back deleted comments.

My deleted (by /r/PowerDeleteSuite) message history popped back up this morning on reddit. Looks like protests are hurting someone's feelings (and...

reddit
@popey What happens if you edit your comments to gibberish? That's what I plan on doing.
@OrangeCorvus No idea, I didn't do that. Let us know how you get on!
@popey I used redact.dev to edit all my comments and to delete my posts. It worked super smooth, the only thing are the subs that were private and now are not anymore, those comments appeared now. Will run redact.dev again to edit the comments. I think it's way cooler to have something like "red musk far-flung important city lock ruthless stone square file -- mass edited with https://redact.dev/" than a deleted comment. It's a stronger message.
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@OrangeCorvus Yeah, I have been periodically re-doing the deletion for the same reason as you.