I consider telling your school's administration "Okay, I'll fix my speech to fit within the guidelines for commencement" and then not doing that and giving the original speech to be a lie.
But we all know that free speech is only for liberal thoughts and ideas; like inserting a Crucifix in urine.
Schools all over the country have been telling students they can't sing carols and they can't pray at lunch and they can't hand a classmate a Christmas card. None of these situations are so. Are they lying or just misinformed?
So let's say that she did lie. Big whoop. The crime of denying her her first amendment rights is far more egregious, and I'll focus on criticizing that instead of a outstanding young scholar. You do as you wish.