oristar classes

Given the reference to "the bright" and "the elite," "classes" could also mean "the upper class" will receive little figurative nourishment (boost).

yes, that does seem to be the implication

I agree. The author seems to be contrasting "the classes" (meaning upper) with "the masses" (everybody else) and not just the students in this classroom.

"... watered down a rigid training for the elite..." is the clue here -- the original lessons were aimed at the upper classes, but have been watered down (simplified) until they don't provide a good education for anyone.