I know that there is at least one active bot (@Mitchell), but I don't know if it works in such a way that it can detect how many new posts someone has written and delete that many posts every day. Maybe there is some new bot that we don't know about, and if it's aimed at Gambling, maybe someone decided to clean up that board a bit. Let's remember the famous bot because of which thousands of user accounts were perma-banned, of course not automatically, but after the moderators had done their part.