I don't know all the specifics of the charges, but it's the sort of thing that the Chinese state has used against numbers of Uighurs in the diaspora. Rebiya Kadeer, who is based in Washington, D.C., has also been described as a terrorist, as an extremist—all these sorts of things—by the Chinese state. Dolkun Isa, I think, faced a similar charge.
I have not seen any evidence to point to him as being in any way connected with violent resistance. He's a politician.