Yes, I think that the idea of studying after school or during a study hall is becoming extinct for most students in American schools. Students would rather talk with other students or get onto their electronics such as their cell phones rather than study, which is why studying is becoming extinct.
Different students study in different ways. Although it is true that some students may not choose to study, it is not true that the practice is becoming extinct in all students. Whether students look over notes the night before the test or weeks beforehand, both practices are still a form of studying, and both are still done.