Graeber was actually an anarchist, not a communist - hence his affiliation with those two spooked up groups. There's a difference - in that one is more favored by the establishment to sew confusion amongst the masses.
He was "poisoned" but the story turned into "early covid victim" from what I recall. I suspected his wife might have been a mole and he simply a true believer. I do believe him to be actually dead, fwiw.
I very much liked his Debt book, though some have questioned its accuracy. He had a panache for articulating the true notion of our occupied politics, which is true no matter your political persuasion.