Schools really can't stop teaching the holocaust, because it's central to the socialist agenda. What they do is distort who the nazis were, and minimize the fact that Jews were overwhelmingly singled out for victimization.
Instead of learning that 6,000,000 Jews, and a couple thousand homosexuals, communists, gypsies, etc... were murdered, students will learn the stories of idealized, fictional characters. ONE Jew, ONE communist, ONE homosexual, ONE gypsy (a black and a Muslim, too, if so much as one happened to die in a death camp). And suddenly the holocaust has little to do with Jews, and is reduced to no more than a parable on the evils of discrimination, and how to suggest that immigration might be bad is that kind of thinking that necessarily leads to genocide.