So....Anarchists with strict rules about what you can say? Lol
You see, this is the problem with the (WRONG) assertion that anarchists are against rules. It's not rules, it's rulers. A sovereign over his own property gets to make rules. Without this, there could be no rule of law, and without rule of law you would have what the un-initiated refer to as anarchy.
While you are mostly correct (I do know the difference between rules and rulers) it reads like it was written by ardent Statists who are afraid of opinions that are TOO far from their own. "Zero tolerance policy" - Please - straight out of the Statist Handbook for we don't want to have to look as context. Turns question how various tenets fit into everyday life into "questions tenets" - you must be statist - are are BANNED. Kinda like public school zero tolerance nanny statism don't you think?
Fair enough. However, I think the question is less one of whether a principled anarchist can have such a policy (and still be principled) and whether it's a good idea. I don't think it's a good idea to squelch speech in general, either--regardless of who is doing it--but I don't think there's any inconsistency in principle. In fact, you could argue that for some purposes, you might want to lock out all the "wrong-thinkers" (only half joking) for the purpose of honing discussion in a particular way.
The purpose for this would be only in a limited context, however, such as a group of people who throw a bunch of money into a hat in order to invest it in some sort of "liberty-oriented" project. If such a group found itself deliberately "attended" and "filibustered" by statists, one may wish to rid themselves. I suspect they want to rid themselves, for the purpose of the type of discussion they want to foster in their circle, of statists. It's not like statists can't enjoy free speech in just about every other context.