Here is my perspective on your questions:
1) There are already Atmos and Auro-3D albums with discrete music in the heights. Kraftwerk and David Miles Huber are good examples. There are some others. For certain types of music, it's very cool.
2) There are albums that mainly or exclusively use the heights non-discretely, but just to "expand" sounds. This can also be very cool and, in my experience, a bit of an upgraded experience over a purely 5.1 mix. My example of this would be Automatic for the People by R.E.M. There are plenty of discrete moments in the surrounds (for my taste), but the music also sounds HUGE, expansive, vast and spacious, at times, in very cool ways. There's an organ during one song that sounds 20' tall, instead of 3' tall. There is something to be said for the Elliot Scheiner 5.1, but the Atmos is a uniquely different experience and one that I love.