This is in the context of his literature courses. There are so many literary authors that aren't white men, that arguing that he should have the right to decide to only teach works from white men (if he deems them to be the best works), does seem to me like arguing that we shouldn't teach the history of marginalized people.
If you only mean non-literary history, the history of black people and LGBTQ people are both very under-taught in United States schools. That's a real thing that some people do want to continue, and argue for. (But this seems a bit outside the topic at hand)