Again, a letter being sent doesn't mean a suit is being filed. The reason a lawyer sent it is because of the potential for legal issues, but by itself the letter has no more force than a "we don't want you to do this, please stop."
The article is devoid of any details and written to paint Crunchbutton in a good light. We have no idea what was actually on the website that prompted the letter. But if I were creating a delivery site for orders to a campus-operated restaurant to campus students, and collecting school ID's, I would think it pretty prudent to run it by the school, even if only for the potential security concerns.