From my perspective this is working as designed. I have a question about intent. Are these incendiary troll posts designed to provoke a response? If so, the only advice you can give people is “don’t reply to troll posts”.
We have a similar issue on some sites where troll posts and all the replies to the troll posts get deleted as unavoidable collateral damage.
Also, how common is it to delete posts in this manner? We need a lot more context.