It could be called a MacBook Air, as a true sequel to the 13-inch model that retails for $999, or it could be a successor to the 12-inch MacBook that released in 2015, which starts at $1,299.
Bloomberg said the starting price of the 12-inch MacBook "put it out of reach for some consumers," so it would be reasonable to expect the familiar MacBook Air branding, especially if it has a similar price point.