Yes. Which is why you shouldn't deactivate your account should you get banned. If you use old reddit and hit all the saved and replied comments you've got, you can remove the stuff that's archived. The most you can remove now is a years worth if you just go back through your comment history. I'm actually digging back through my own vintage mac posts and copying out my best tips and will reupload them here at some point.

oh definitely, when I left reddit (ahead of the curve), I made sure to mass edit all my comments and posts and everything I could find one way or another, to leave as much shredded garbage behind as I could. But I still wouldn't be surprised to find them analyzing the time of such mass edits and preserving a snapshot of content from a user before such an event.