You don't have to go to class, but if the teacher calls the roll, it will be considered absenteeism, and one or two absences will affect your usual grades; It is much more spacious here. If you meet a strict teacher, you won't be allowed to take the exam.

As for what universities do, as long as they don't violate laws and school rules, they can play and learn by themselves; Of course, if you play for four years, or if you don't learn the ability to settle down in the future, you will have to bear the consequences yourself.