Fear for his life, probably. He seems to be popular enough to give those parties a momentum that would make him a target of both the capitalist parties.
Black Panther party members — including its leader — were killed by the FBI. A genuine threat to capitalist rule will naturally have to face these threats.
People on twitter are saying he’s actually a far-right nationalist hypocrite who owns properties in the US. Makes sense to ban him then ig; just one of those fake internet celebrities that they occasionally ban probably.