Good for them. Nobody should WANT blacks to be dysfunctional. I've known African immigrants and more often than not found them to be hard working, disciplined, and easy to get along with, with some exceptions. I've also almost never found them to be anti-white or angry.

Could this disprove "white supremacy" theory?

I have no idea and don't care. I don't even really know what white supremacy theory really is. Whites simply advocating for themselves or speaking out against slander and obvious discrimination, or who dont actively hate themselves, are usually labeled white supremacists by Jewish supremacists and their countless lobby groups, so the term really has no meaning anymore.