You can argue that maybe the person don't hate white people and is just joking or whatever, but those are objectively racist tweets. You can also argue that racist towards white people is less harmful, because privileges and shit, but it's racist nonetheless.
But we also live in a word that joking about stuff or singing rap songs that contains the n-word is automatically considered racist/hateful and the person is dogpiled to death. We can't have it both ways.