No, only the 1st 4 would be flown to mobile. The rest would be assembled there, then modified by Northrop. The KC-46 will have significant foreign content as well, how much? Who knows, but the 787 is around 50% foreign content, if not more.

As an aside, I was talking to one of the managers at mobile aerospace and he was very worried about airbus winning the tanker. He said it would significantly increase his labor cost as he competed with airbus for mechs and engineers.