Brandenburg v. Ohio and Dennis v. United States provide a pretty clear legal standard for this:
"The constitutional guarantees of free speech and free press do not permit a State to forbid or proscribe advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action."
Twitter, of course, is not the State and can do what they want.
But if the State censored or in someway punished Jones, they would have to demonstrate that his speech constituted "inciting" "imminent" "lawless action." And there have been several cases since which have focused mostly on the "imminent" part.
"The constitutional guarantees of free speech and free press do not permit a State to forbid or proscribe advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action."
https://www.law.cornell.edu/supremecourt/text/395/444
Twitter, of course, is not the State and can do what they want.
But if the State censored or in someway punished Jones, they would have to demonstrate that his speech constituted "inciting" "imminent" "lawless action." And there have been several cases since which have focused mostly on the "imminent" part.