All of this is true - but at this age there are plenty of children who want to be dogs, and stories abound of children who are wizards, children who find magical lands, children who find dragons in their house. I can see, at a stretch, how this book might be the starting point of a conversation some parents might not want to have - but I think that's a stretch.

I think what's most important is that kids aren't shielded from complicated concepts - but introduced to things at an age appropriate way. I think your argument is valid though, it might be a stretch but isn't entirely outside the realms of possibility.