That's the key, all this crap getting retconned. I dropped the book almost immediately so I have no idea what's going on but I'm assuming a sort of 'back door' has been left regarding the unnecessary aging of Jon--when Jor El is returned to his proper place and role in the timeline and this Oz stuff is undone, he will have never taken Jon away to begin with. I've no idea if this could even somehow work as I've not been reading the book.