My HS rolled out iPads to all students my Sophmore year of HS 4 years ago.

It was well known the average GPA dropped by a sizable amount (mine personally by nearly .5). There wasn't a good way for the school to lock down games, and it was really hard to self regulate. The technology side of Canvas worked pretty well once teachers knew how to use it, but the fact that so many games could be played just distracted the hell out of everyone, and the teachers knew this. Without a way to lock down device gaming, I don't think they're a good idea in a school environment unless you antipate and actively try to curb gaming, but this can be hard and will make the teacher seem like the bad guy, which is never a good thing.