Pretty sure the new doors are are galvanized. Not a heavy coating like you would get by dipping it but the new style galvanized coating that they use on the new cars.
Also the door and skin are made of steel so less concern about dissimilar metals and the frame is stamped so no welds to break.
Also the door and skin are made of steel so less concern about dissimilar metals and the frame is stamped so no welds to break.