Camping, yes.
School, no.
Junior school kids should not be allowed a phone in school.
If there is an emergency, you would be expected to phone the office so an adult knows.
When he is under your care, it's up to you.
If you think he has enough freedom to play in sight, then he probably won't need it.
And what if he shoves it in his pocket, climbs somewhere, then jumps or falls, landing on the phone and breaking it?
I say keep it for emergencies, but don't rely on it.
My ds was given a phone at 9, when I was pregnant. I fainted while shopping. He had the phone for my safety.
But he still manages to get to and from school alone without it.
If your ds can't get to the school gate without a phone, does he have other issues?