At a university level that's a pretty reasonable rule to have. Hell, even during exams, why confiscate? If the phone would be a means of cheating, the rule should simply be that using one is an immediate fail. That's how all my university classes did it, if it wasn't an open book exam, all phones were to be placed either screen down on the student's desk or left in their bag.

Worked perfectly fine.

I only ever had one class (which wasn't an elective) where computers and phones weren't allowed even during lectures, which was ironically an intro class on programming in C. Was a waste of time because the professor sucked and for me doubly so because I had already been using C for many years by then. Attendance was also mandatory so I just sat in the back and mostly slept through it.