This is basically the S-class phone (To make a car analogy, because that's what we do). The S-class Mercedes costs twice as much as the "Normal" E-class, and each time they launch a new model, it contains the most exotic and expensive new gadgets. It's sold to the very price insensitive. This offloads a lot of the R&D costs of these technical gadgets to the S-class customers. The following year, their E-class (Which is upscale but not a super luxury car) sees most of those S-class features at a much lower price point.
I'm suspecting this is what will happen with a new, expensive iPhone. It will be a testing ground for new features, and if the features work they will be introduced at much lower risk and cost to 10x the number of customers next year. This year it's oled screens, facial recognition etc.