No, they do not have to join the military, but many do. Cadets who earn the Billy Mitchell Award may enter the Air Force at an advanced grade (E-3) if they choose to enlist. The service academies and ROTC also look favorably on CAP experience. Approximately 10% of the USAF Academy cadet corps got their start in CAP. But no matter what career you choose, the skills you learn in CAP will be invaluable.
Are they expected to join the military?