Telling someone else what to do, or not do, is off topic. The topic is the company. It's impossible to make a list of every possible TOS violation. Instead ask "Is this about the company". If "no". It's off topic. However, general neutral chit chat conversation is ok. "Have a good weekend, I'm going hiking." "Good to see you Amy" etc...
Is there a TOS rule that say you can't "tell someone to stop bringing something up" again context is that I dispelled the comparison.