Is Dunman High right for doing this

Students in Dunman High School are no longer allowed to use their phones at all. This includes during lessons, free periods and EVEN RECESS. Is this too much coming from the school or no.

Context: Dunman High has banned the usage of mobile devices for all their y1-y4 students (Sec 1 - Sec 4). This includes break times such as recess and lunch. Students are now forced to hand over their phone at the start of the day.