While employers might be told to do this, common citizens can do as they please. Especially at a public university, which is required to respect the First Amendment (although they tend not to).
Employers can’t be told that because it’s a lie. “zir”, “hir”, etc aren’t words. They’re not in the dictionary. They’re certainly not in legislated national code. Most people have never heard of those arrangements of letters, and most of those that have don’t know what they ostensibly mean.
The ONLY place this has any smidgeon of truth is NYC, where there is a “you have to call ‘em what they want to be called” law, which still fails because beyond “she” and “he” nobody knows what those terms are, haven’t been told, they’re not words, etc. Unless someone’s got it declared in legal writing, and shows that around, “claims” of bent gender mean nothing.