Interesting man. I think as the world becomes smaller at a faster rate, we are seeing a BIG transition to more and more fusion. Culture (containing art, music, language, ...) has always been a result of fusion. It's getting harder and harder to create a new 'genre' - because all the genres are here already, and thanks to the internet things are mixing up.
I believe in subgenres though! Like the subgenre in hiphop perfected by the likes of Kanye West, Kid Cudi, Drake, ... lyrical, emotional, spiritual, personal, real life stuff.
RE: The 50 Year Lifecycle of Music Genres