I agree, and the obvious point that follows from this agreement is that there is nothing 'missing' from the copy. Both the original and the copy have what you are calling "ME". There would be two, unconnected but identical, YOUs.
Nothing is missing, nothing distinguishes the original from the copy.
Wilber claims that experiments show that small children look at 2d shape and size to determine bigger/smaller & more/less, but as they get older, they learn to conceptualise volume. I don't have the time right now to check if this is the case, but I'm not sure what you are illustrating with this.
ETA I did just make a quick check on the book that you got this from, and also looked at the original experiments that Piaget and others did. It is not quite as simple as Wilber claims, nor does it follow that one must have a higher, broader or more developed understanding to believe in souls or immortality.
Are you positing that you are unable to conceptualise materialism, or are you positing that sceptics are unable to conceptualise souls? And that one side or other needs to broaden their understanding? Because I don't think either of those is the case.
There is nothing wrong with holding the opinion "I am immortal, I have a soul which will continue past my physical death" as long as you also recognise that it's a faith-based, evidence-free position.