Have not noticed such before but the other time this happened to me was when moderator deleted all of my post I have made in the past I don't know if it was due to some scripts they are testing.
You have been in the forum since October 17, 2017, and don't even know how and why posts are deleted in the forum. In fact if you had read a few replies above yours you should have known why, but instead you went ahead to speculate about script testing
Think this is different. The user has had 28 posts deleted from their account (which accounts for almost 10% of their posts!) but it could have been a mass clearing of insubstantial replies. If you take a look at their post history, there is a plethora of one-liners (
example) and I can presume that someone went to report their post history.
Sometimes, I do the same thing when I encounter egregiously bad spammers - it's better to root out a high concentration of spam via users rather than via boards and threads