Don’t think common core has anything to do with it. Wife worked at a school, if one kid says he/she need to use the restroom, then they all need to. spreads like wildfire around a classroom.
So in a way I can see some reasoning behind this, but you can’t maximize your time if you got to send a kid to the nurse or get a custodian in the room for a clean up.
Kids act like that because they are caged like zoo animals and treated like a manufacturing product.