Does modern music really sound the same?
I agree with the researchers to a point: the key word is "pop," as in music distributed by mainstream labels. Independent recording and publishing, the latter via the internet, have exponentially multiplied the variety of genres available to listeners — many of which, like ambient and soundscape, are non-belligerents in the Loudness War. Then there are traditional modes, like bluegrass and chamber; by definition eclectic.
There's some irony. Music today is probably the most diverse it's ever been, care of new technologies and ways of thinking. Yet one has to step outside of the old establishment — centralized media — to discover it.