I would argue college gymnastics is exactly like most other college sports. College swimmers don't learn new strokes, they get more efficient with their breathing, better technique on starts and turns, more powerful kicks. College basketball players don't learn new skills, they get more efficient with their shot making, develop more aggressive defensive techniques, become better rebounders and passers to help the team.
Even if a college gymnast does not learn new skills(and some do), she may be developing better technique in her tumbling to make it higher, cleaner, with more controlled landings. She is developing the technique in her release moves so they are cleaner and caught every time, becoming better at hitting that handstand on bars every time. She is perfecting that Yurchenko to get it more explosive off the table, cleaner in the air, sticking that landing consistently. Getting better doesn't just mean "new", it means more consistent, more explosive, more dynamic, cleaner.
Only sport I can think of where many college athletes might learn entirely new skill sets is diving, but that's because many athletes come to the sport late so are still on the learning/acquiring skills curve in college.
College sports are team sports. The whole team is working together to get the win. In gymnastics, helping the team means perfecting technique so it's deduction free, hitting consistently every time, doing your best to stay healthy and injury free so you can contribute, stepping into the line-up at the last minute because a teammate was injured in warmups, learning to hit a routine with thousands watching and the team relying on you.
While most college gymnasts may be past the learning new skills part of their gymnastics career, they are most certainly striving to get better.