I have heard conflicting versions. Some people are saying it seems that the locked-down subs are the ones where the new comments aren't sticking. Which makes sense, but who knows what the truth is. None of us can trust anything Reddit or /u/spez says ever again, so it could be malicious or it could be technical.

My edits weren't reverted. I think it depends on what tool you use. There's a fork of Power Delete Suite that adds a 5 secs timer to be in compliance with new Reddit rate limits and it seems to work.

I have made multiple attempts to delete my reddit history. I tried shreddit, Power Delete Suite, and redact. The history kept popping back up. It got restored in waves, subreddit by subreddit.

Many people have said that the problem relates only to subreddits that went dark and this is not true. I had history popping back from many different subreddits, whether or not they participated in the blackout, and even after the blackout ended.

Finally with redact I tried modifying all my old posts rather than deleting them. That change seems to have stuck for now.