It seems overboard to classify the mere labeling of oneself anti-gay as hate speech. Would this apply for example to the username
anti-x for various labels
x that can be applied to people, for example christian, atheist, homophobe, etc? At any rate, the more unarguably germane issue is that the username is disruptive and inflammatory, not to mention poor taste. And there is an even more germane reason for suspension still at hand that is unexamined here.
Edit: I agree my given examples are weak and do not have the force and quality of "anti-gay" or "anti-black," but my understanding is that hate speech is beyond being factually wrong, morally wrong, or universally offensive $-$ it is hostility, harassment and incitement at criminally culpable levels (think drawing a cartoon in the US condoning a black man hanging by a rope around his neck). My impression is that a single username like "anti-gay" or "anti-black" is too passive and not nearly communicative enough alone to reach a level that it can be called hate speech.
It is clear to some of us that the user "anti-gay" is the same as the user "Twink." The account Twink came into the chatroom evangelizing tolerance for gays (something nobody voiced any contrary opinion to) to the point of disrupting conversation, and randomly calling others racist, homophobic etc. Here we see an account anti-gay basically manifesting the same exact behaviors but from the other side of the political spectrum. Both appeared in chat within days of each other using the exact same MO to troll (and as Twink this user explicitly admitted to trolling).
The disparity tells us that we do not actually know what this user's opinions about gays and gay issues, or really anything, truly are. Everything s/he says is performance art for the purpose of entertainment, so we cannot take what is said at his/her word. Ultimately, this user is testing us and amusing themselves with our extracted responses, probably reveling in the power of being able to cause such consternation at will. This is probably the most notable aspect of this situation.