I think his names Jett ...
Have heard that argument a lot, that if he wasn't prem then she'll be keeping him out of the spotlight to give the excuse why he doesn't look it. My problem with that is surely he will look even older by then if he was born full term and it'll be noticeable. Premature babies don't "catch up" for 2-3 years.
He had quite a good weight at birth, so he will catch up within weeks, at least physically. However, since he had problems with his lungs, I can imagine he will need careful monitoring for quite a while and Katie will not be able to take him to Australia next month - it is far too risky.