I agree with you.
We did buy the book and my daughter is reading it first. From what I’ve gathered, he did reveal things that he would not have anyway of knowing (like he had a sister who died before he was born), so that makes me think there is truth in what he says. HOWEVER, kids are kids and embellish and give discriptions that either they think we want to hear or match what they know of. So I’m not equating everything this boy said as the Gospel truth, but a glimpse “through a glass darkly”.
Yeah, I noticed on the GMA interview the kid even says it’s hard for him to remember all the details, so it wouldn’t surprised me if he felt he needed to stretch things a little to make a good story.