I went and saw the movie as well. The BLM revolution by force was roundly rejected - and yes, a white guy was seen as an ally above the main promoter of revolution by force.
To be fair, it is a comic book movie - but if one can suspend disbelief about Norse Gods and a suit that is years head of us technologically, you can suspend disbelief about a completely unknown civilization.
... that speaks perfect English, often with a slight British accent.