And there really was no purpose to saying he was a former student.
Except that they make a point to stress Beast's former involvement with Xavier's school and could possibly contradict something from the other two movies which are in continuity with each other because of plot points carried over from one to the other.
If Singer completely ignores Superman II, III, and IV, then I'm fine with that.
But if his plot thread is going straight from StM to SR and completely contradicts something established in StM then I will argue the same side I am arguing now. If Singer chooses to pick and choose what he wants to keep from the other movies, then I will also argue that.
My problem with X3 was that it is a direct sequel to X2, using plot points from X2, and contradicting something shown in X2 and not explaining it at all. If Ratner had chosen to disregard X2 altogether and just pick up from X1's plot points, then I'd be fine. But keep the movies as a whole. If you're going to continue a movie, don't pick and choose what you want to keep and ignore from the previous film your using as your base.