The main reason you don't hear much about them anymore is because they don't show anything.
Perhaps it should be retitled "how magic leap might work"
Personally I limit what I consider AR to be graphics superimposed on a real world view. With the maps in Pokemon GO, the real world and game are distinct, almost like VR.
With AR you could do all kinds of kind of socially awkward crap. Can you think how cringe inducing AR Tinder would be?
I mean...miniature cameras are old news and they're a lot easier to hide in ways where people don't realize you have a camera. Just as there have always been ways to track stuff like location and purchases via cell phone location and credit card use.
The stuff in Pokemon isn't much "creepier" than what your average map app or social "gamifying" app like Foursquare does.