A lot of musicians graduate from music school with degrees; but, aside from teaching positions, they are NEVER asked to produce diplomas at audition: it's "Can you PLAY, man?"
Next time you're on a cruise ship, go up at the bridge: look for the blond with the gold stripes on her shoulders and ask her is her dad is "dasboot". Then ask to see her highschool diploma!
However, you said they took SATs and college entrance exams. Would you have made a fuss if they were told they had to? That may the difference between accredited schools and the non-accredited (Bob Jones U).