I agree that it’s not optimal, and it’s not a great lesson about keeping your word, but it seems the student could pull out since no harm is going to come to the school by his backing out (since he was not recruited).
If the student is waiting for a financial aid offer, maybe when it comes, if it is less than was indicated on the NPC, the ED offer could be rejected on that basis, since that is an acceptable basis.
But I don’t think a student should be locked into a 4 year contract that benefits no one and may actively harm the student if he is intent on playing the sport, because of a “priniciple” when the principle itself is designed to benefit the universities at the expense of the students. The student has one life while the university has many students to take that student’s place without affecting the team or the coach since the student wasn’t recruited.
Finally, I would wait a while before deciding what to do; research the other school, visit with the coach and the team and see if it is really looks like a wonderful group and a positive coach and a real opportunity to play. The first school was apparently a great fit a month ago, and you don’t want to make a decision to break a contract and choose a different school when this month’s emotions may also change.