Yes they should offend their students because history is offensive.

We should also teach about the Holocaust and read the uncensored version of huckleberry Finn, even though it may be offensive.

People (students) will be offended but they will learn how history has changed, be able to think for themselves, and not fall into ideological line. If this scares the left/right establishments that is a great thing.

Living in a 1-party state would suck.

The question wasn't whether the teacher was allowed to talk about things that might upset a subset of students. In some cases, like talking about the Holocaust or slavery in the US that will not be possible to avoid entirely. The question was this:

> If a student asks a teacher not to call them something that offends them, is the teacher required to stop using the slur?

If a teacher calls a student a slur, or otherwise directly addresses the student using a slur/derogatory term, should this teacher stop doing this? Stop moving the goalpost.