I would say the function of history is to make students aware of how atrocities come to be, not judgement after the fact that this or that atrocity was wrong. Atrocities are only symptoms. It's more important to examine the disease.
But talking about atrocities as the symptoms of a disease still implies value judgement. If we don't ultimately put value judgments on anything at all, then why does it even matter how anything came to be, and what's the point of studying it?
Surely one of the benefits of studying history is to help us avoid repeating the mistakes of the past? If we are not going to acknowledge anything as a mistake, then what do we gain by studying a collection of facts about stuff that doesn't really matter.
Are you really saying that you don't make any judgment in your mind about the Holocaust in terms of whether it was right or wrong? That you look at it merely as a fact of history, neither good nor bad? Or is that suspendment of judgment just an artificial thing that you expect people to apply in their history lessons, and they then resume normal human reactions when the bell goes?
And yes, maybe I'm being absolutist about it, but fuck moral relativism, it is a normal human reaction to think that the murder of millions of innocent people was wrong, and no amount of philosophical argument will persuade me otherwise.