The university has a code of conduct and can expel students for various infractions.
Somewhere someone is making a moral judgement. Not sure if restricting "speech" before the fact is a workable argument. This is one of those broad gray areas that are difficult to nail down as to what is exactly the right thing to do. I guess it all depends on what "conduct" is, and whether it can be regarded as advancing an idea or has a political component.
I should not be surprised to discover that "conduct" codes are going to be/have been slowly modified until they conform to modern PC Liberalism.