Our school allows for it, but our classroom has made some adjustments partly because they are only there for 2.5hrs ,the other part is because sugar and kids are not always the best mix for learning. Yes, sugar happens, however have you seen a classroom full of kids hyped up on sugar? Even if only one or two kids get hyped the other kids feed off of that chaos and the classroom, even with the best of teachers, can go into a tailspin. So, my son's teacher's adjustment has been that the ONLY cupcakes/treats allowed are MINI versions so, mini cupcakes, cookies etc. In addition they take them on their way out the door. They sing "Happy Birthday" during morning meeting and have whatever treat it may be after coats are on. I appreciate this as the mom who has that kid that does get hyped up on sugar, I can choose if he has it, how much of it he has etc.
I simply suggest you celebrate at home and leave school for learning OR go with the fruit skewers or use cookie cutters on melons (if you can bring from home). Even then, leave strawberries off the list that is a fruit allergen many do not know about.