I took my son in for some testing and overheard a teacher and principal discussing banning them. I think it’s happening a lot of places. My daughter says practically everyone at her middle school has one.
I have found it to be a fairly distracting fidget during schoolwork (he’s homeschooled). While we’re watching videos or during “hands off” activities like that, I’ve found a small ball of play dog to be a great fidget that doesn’t take away any focus.
I do love the fidget spinners for times like car rides, waiting rooms, etc. I have tried to really cut back his use of electronics during those times and fidget spinners have been a surprisingly good help.
I could see a fidget spinner being useful perhaps during some of the long awards assemblies or things like that at school, or during the bus ride home (although I know they often ban those kind of things on the buss too – my son wasn’t even technically allowed to read a book during the bus ride home). Try contacting the principal to discuss your concerns.