Hair cut or different school

My son is in 2nd grade he is in a private school, he has hair pass his shoulder his choice. His school said it’s needs to be cut to neck length. The school also require the students to dress casual 2 a weeks which I knew from last school year. I think we should cut his hair, my husband says no and to switch schools. I believe early education is important. My son is smart and loves his school. 10-15 kids in a glass so it’s perfect. I’m thinking cut his hair and get him a good education. I asked my son what does he think he said he wants his hair but also wants his school and friends. I told him it will grow back. I need do what right for my son, but I also don’t want the school making hair decisions for my child.