They're all on TOR now, and even there they get regularly busted due to shoddy opsec.
Example: Almost any of the various image booru sites have it, usually behind a checkbox.
And it incites harm, which is one of the restrictions that can be placed on speech.
But that doesn't have anything to do with constitutionally protecting 3rd party nations using platforms/speech for propaganda in our (or any other opposing) country.
Seems ridiculous on its face to try to confuse or equate the two and argue the point.
I put it to you that most fair minded people are also pro-censorship.
It's a powerful tool (which I personally vehemently oppose) but even if you think censorship has its place, it should be somewhere with oversight, due process, et c. ISPs are not that.
The obvious failure mode can be observed presently in Russia.
Musk is not anything like a free speech absolutist. He makes extensive use of NDAs and other speech restriction agreements for non-security non-trade secret reasons, and one time it seems he swatted a whistle-blower.