I think you have to separate what happens on AB from what happens in the wider world. AB (and for that matter, many other internet settings) is, to me, the virtual equivalent of walking into somebody's house. Well, it's their house, so stick to their rules, right? Sure, AB, is quite a large house with a varied spectrum of guests, but nevertheless it seems to me that the analogy is one to bear in mind. Presumably if it were your house you'd like people visiting to respect whatever boundaries you see fit to impose, or not. Same in the other direction. I don't think this is in any meaningful sense comparable to "newspeak" -- it's just common courtesy, to other people who use AnswerBank as well as to those who run it.
Actually, for that matter I'd say the same thing is going on in the wider world. People are becoming more aware of what should always have been recognised as a universal truth, that in general it's not a very nice thing to be rude, offensive and just downright disrespectful of other people's feelings, opinions, lifestyle, personality etc etc. Very probably that will lead to things going too far on occasion. This is natural -- whenever there's a change in social habits things tend to swing violently around one way and the other before finding some sensible balance. The key thing that separates the current situation from Newspeak, though, is that in the wider world no-one is really in control of what you can and can't say, except society itself that is gradually becoming less tolerant of intolerance. Certainly, the (current, UK) government isn't in control -- "hordes" of migrants, anyone? -- and, despite concerted efforts, the loud minority of people who might support such aggressive censorship are yet to be taken seriously by the wider community.
Returning to an earlier analogy, I think it's better to view societal development not as a slippery slope but as a (damped) pendulum. For a very long time, as has been pointed out, the exact opposite was the case (ie you could be as rude as you like to certain of the population and hard cheese to them who would have to both put up and shut up). Or, for that matter, things were already newspeak-esque -- woe betide anyone who dared to insult their lords and masters. In both cases things have tended to swing the other way, with less deference to authority and more concern for others. In both cases, too, things may have swung too far -- but then, hopefully, the pendulum will eventually start to return to the balanced middle, where we are indeed after all free to say what we like, but choose not to.