My daughter had a lot of fun in Edge when she was in that age group. She liked it so much better than the younger age club. Make sure he goes the first day because that's when they do a lot of the ice breaker type get-to-know-you games.
My daughter always had to have her phone with her. If she was leaving Edge, she had to tell us where she was going immediately. She was allowed to be out and about on her own, but she couldn't just be roaming the ship. She needed to have a destination like "I'm going to get ice cream with my new friend." She was not allowed into anyone else's cabin and no-one was to go with her into our cabin. And yes, a couple of times we did check that she really was getting ice cream or shopping or standing in line for Goofy or whatever it was she said she was going to do when leaving Edge.
They have a lot of great activities in there and then also just chill time to play games, do whatever choice of crafts they might like, etc.