I mean, they are so used in NTR and NTS that actually simply having a normal black man would be a novelty. Like seriously NOT every black guy in a porn game need to be hund like a horse on steroid.
But I agree with the idea that having a different skin color in general would certainly mark a scene or a bull as different, it doesn't need to be only black either, could also be obviously middle eastern, to give some body variety to Laura bulls. And there's no need to transform them into insane porn caricature of themselves either. Just normal people.