Yup it happened, back in 2016 during the elections. He edited comments (and posts I think) in r/the_donald, people originally said “f*ck spez” and he edited them with the moderators usernames. Things like that.

https://www.theverge.com/2016/11/23/13739026/reddit-ceo-steve-huffman-edit-comments

Now, let me just say that I am aware of how toxic that sub was, but regardless spez opened a bad precedent