Gadsby has declared the dominance of the white male comedian to be over. How racist must she be if she thinks white men have dominated comedy? Any conversation about great comedians includes a long list of non-whites. Just because she doesn't know who they are, doesn't mean they don't exist.
I don't think being racist is her intent, I'd argue she is ill informed, ignorant and naive.
If anything she claims to be anti racist, labeling white male comedians as "dominant" and painting them as toxic is ok in her view because they're white males. You know the oppressors of the world.