That, actually, has nothing to do with that BS "paradox" and well predates it. Indeed, you can't do illegal things, and inflicting violence on others is generally illegal. What the "paradox" is used for is to silence those with inconvenient opinions -- if you've followed discussions of the Damore affair, "paradox" has been trotted out as justification for "punching him in the face" multiple times. But on the other hand, to use the simplest example, US is quite tolerant of speech (in the 1st amendment sense) and hasn't turned into communist or other dictatorship. USSR, or China, or Nazi Germany on the other hand did not tolerate any "intolerance" -- that did not turn out too well.
Indeed, you can't do illegal things, and inflicting violence on others is generally illegal.
If someone is consistently threatening violence at some point you need to make the determination about how to deal with that. You can of course do nothing about it but if the person eventually goes ahead and commits violence you now have a bunch of injured or dead people, which seems a worse ill to me than deplatforming.
You think deplatforming is going to stop him from killing people? It might make it more likely - he may convince himself that the deplatforming is part of the great conspiracy against normal people, and he has to strike a blow against it. (On the other hand, it makes it harder for him to convince others to join him.)
Don't deplatform him. Investigate him. Get a warrant and find out who's listening to him. Find out what's going on in their private communications - are they making actual plans, or are they just talking?
Deplatforming is about the laziest and least useful possible response. As Fins said, deal with the violence (including plans to commit it).
If someone is threatening to commit violence, there are already perfectly effective legal ways of dealing with it. If anything, if you do deplatform them , noticing that speech becomes significantly harder, while they become more radicalized (and if Zuckerberg did not exist, anti-semites would have had to invent him; but he does exist).
To go back to the original article, though, it is interesting that they are banning white nationalist content. Does it mean that any other nationalist content is just fine. And can I start an Even[0] separatist movement on FB, calling for eradication of the whitey? We'll start with Russians, of course, but after them we're coming for you! /s
If I didn't have better things to do, a conspiracy theory of FB (they did elect Trump, as everybody clearly knows) being in cahoots with Stormfront and specifically calling out whites to stir resentment almost writes itself here.
Are you advocating for Facebook being legally barred from banning any content on their platform that isn't explicitly illegal? That's the only alternative I can think of.
Actually, I am for Facebook having the right to ban anything and anyone from their platform. But that does not mean that doing so would necessarily be a good, or right, or moral thing to do.