I'm reading it. It says 11th and 12th grade is when you can branch out. Kids are taking college level classes in 10th grade at our school. My children were behind others by waiting to taking AP Calc in 11th grade. Why would anyone want all students to be on the same course until they reach 11th grade?
Our kids are not offered college level classes until 11th grade here.
They do have the option to take honors classes from 7th grade on (although I believe math honors starts in 8th), however it is the same curriculum as the "regular" class but a faster pace and a more aggressive work load. A student can choose to go in to honors based on their grades, but if they do not they are still eligible for AP classes in 11th (based on their grades from previous years).