Yes he is, and the Ark case has nothing to do with that. He is a natural born citizen because according to the law in place at the time, birth overseas to parents, both of whom are U.S. citizens, makes him a citizen at birth. AKA, natural born citizen.
Almost right, but profoundly wrong.
"...according to the law in place at the time, birth overseas to parents, both of whom are U.S. citizens, makes him a citizen at birth." True.
"AKA, natural born citizen." False. The status of "natural born citizen" does not depend on the operation of any statute, and indeed cannot, or a new statute could take it away. Whatever the citizenship status, if it depends on legislation, it is not "natural". "Natural-born citizenship" is a citizenship status that derives from the operation of natural law independently of any statute, and which cannot be removed by statute - or any act of man.
This is the view of the fremaers, and it is the view of the drafters of the 14th, and it ought to be our view if we wish to be true to the Constitution.