You could ask him. At 7, I guess I would trust his opinion.
There are videos of it on youtube, so you both can preview it and decided from there.
The special effects are pretty cool- the mirror, the wardrobe and Lumere are all pretty neat, so it may be something he might want to see in person.
Its an interactive show, they pick people from the audience and then put on a show. its cute and fun, but interactive shows aren't for everyone. The people who get picked, get to have their photos taken with Belle. They picked me to be a guard and my son to be a dish. They asked if there was anyone else who wanted parts, so they have enough parts for the kids, but the adults mostly watch.
IDK, we liked it, but 7 year olds can be tough. I would just watch part of the video and see what he says. I would not wait for hours for it, so I would either use a FP for it, or skip it personally.