I was told by my son, that some teachers will actually ask the kids to do things on smart phones. And it's true, they have occasionally asked the class to do something requiring a smart phone.

If this happens, you need to raise a fuss about it. You can change things. Make it difficult, make them have a loaner smart phone (a pain in the rear to keep charged and available for everyone) to prevent your kid from being excluded.

This whole area is in a state of flux. There's also classes where supposedly the smartphones have to go in a cabinet, not to be touched by anyone during class time.