Depending on your state requirements, many schools have gone to several "grades" or levels of diplomas. That's because some state requirements were set so low that other than a state college that must accept anyone with a diploma, the students weren't prepared for college. And even at those state colleges that "must" accept the graduate, they didn't have the credits to get into a matriculated program - they were just "accepted.
There were three levels of diplomas at my one son's school - AP, honors, and "standard". It was actually possible, by taking a lot of AP courses, to have a GPA higher than 5. His is a honors - he was higher level tracked, but only took 2 AP courses.
Basically, to answer your question, it is entirely possible that a particular school has decided to require more than state minimum. Many have also laid out particular classes required (i.e. 4 years of language, 4 years of science, etc.) instead of state minimum.