Why didn't they....
Just continue the first movie into college instead of re doing it with the exact same people? I mean I know they couldn't get Mike J Fox back after back to the future, but they had to know no one would buy the entire basketball team (including coach and token best friend) would switch to boxing and go to college together lol.
It would have been much better if they just used a new actor to play the MIchael J Fox role and continued the BASKETBALL story into college.