Yes, the banning of peanut butter is present in most all schools now. The cooks at our school are not allowed to serve it or even use ingredients which include peanut butter. I have a jar of peanut butter in my desk which I eat for snacks during my break, but next year we will have several students entering the middle school where I work who have the severe allergies to it, and I won't be able to even have a sealed jar in my desk.
I'm sorry for your son.