Looked through the discograpy and reading the article now. It's interesting, but this is a huge overstatement, seemingly to push the Henderson/Tyner 'Forces of Nature' release?
"Between the death of Coltrane and the death of Morgan, there is a dearth of great material in the recorded canon."
Blue Note, Prestige, and Milestone were cranking out great records between 1967-1972, and other labels like Atlantic were also putting out good jazz records (Charles Lloyd, Herbie Mann at his most adventurous, Roy Ayers, etc.) Columbia was releasing stunner after stunner by Miles Davis and had some other great albums by John Handy. And Capitol had Cannonball doing his thing. Plus a lot of beautiful music was being recorded in Japan during those years and ECM, Freedom, BYG-Actuel and other labels were active in Europe. Iverson seems to have an agenda, and seems to be intent on coloring reality to fit his agenda.