Just like the "if OP asks you to leave due to profanity blah blah etc" rule thing has been modified by the Devs. You have to leave if OP asks even if you did nothing.
So maybe dev's changed that part of the rules when it comes to hate threads. No mods have ever came into a hate thread saying "Making a hate thread is against TOU you will be silenced" that I've seen. They always encourage to make a seperate hate thread when a regular thread turns into a hate thread.. And they dont get silenced if they do make the thread.
Ok, mods have commented on hate threads also. And dont silence anyone. So it's obviously ok. Never seen a mod silence on a hate thread like this unless it gets out of cotntrol.