academic issues - UC puts its foot down
UC sued for rejecting Christian Academy syllabi
Well, sometimes it bites.
Yes, private schools can teach whatever they want, and Universities, including public Universities, can conclude that in their professional assessment the syllabus or academic content is inadequate and that the grades the students earn are meaningless for admission purposes.
There are plenty of private Universities the private schools can affiliate with or petition.
Don't know what a student from certain "Christian Academies" would want with going to a den of sin like UC anyway... they might accidentally take a evolutionary biology or cosmology class and learn stuff.