There is already a precedent from decades ago. The U.S. and pretty much every developed country on Earth have laws against distributing and possessing child pornography, because child pornography creates a market for exploiting children and selling the recordings online. The universal consensus is that this kind of expression needs to be restricted in the strictest possible terms, because it causes material harm to disadvantaged people. Nobody loud enough to be picked up in the media bats an eye at this reasoning for sanitizing the open Internet of such content, and online the words "illegal content" have become more or less synonymous with child pornography. Researchers looking into the subject to study its actual effects have been ostracized themselves because it's so hated. Its illegality has entered the realm of common sense at this point. So maybe there exists some extreme in terms of what you can post online such that if you disagree and insist that a certain class of content needs a platform because of reasons relating to "free speech," you will be almost universally disagreed with and vehemently ostracized. That's why the deplatforming doesn't surprise me much.

But determining what counts as inciting violence is harder to determine. You can't post images of children that were actually exploited and later declare with plausible deniability that the content of those images were not to be taken seriously, because they act as photographic evidence of a crime. But how many people that post online about hanging a politician would really act on those words if the politician was within arm's reach?

It's another question as to whether or not child pornography incites child exploitation, instead of just incentivizing it, similar to the argument that pornography incites rape. But it seems to be agreed on that humanity would be better off without it entirely, to the point of very harsh legislation. I'm wondering if this is the direction some people would want to take the spreading of misinformation and alleged incitement. I wonder how many people who distribute child pornography would change their outlook on it in the face of evidence.