So given the hypothetical, you wouldn't want an Asian woman voicing Nadine either? Only a black woman can voice black women? White men can only be white men, black men can only be black men?
I don't buy that really. If anything, you're limiting people even more and creating more barriers. Part of the really neat aspect of voice acting is that a VA's physical appearance or historical background has no bearing on what kind of person they can portray.
That's a fine idea, but then in practice we should have way more minority actors and actresses voicing white characters. I think we'd have an extremely difficult time finding an Asian VA for a white character in anything.