> Things like this make me very skeptical that the accepted model is correct.

To which "accepted model" are you referring – the cosmological model for the Universe, the determination of black hole masses, the formation and growth of supermassive black holes, or something else? As @nilkn notes, this discovery is in conflict with existing models of the formation and growth of (some) supermassive black holes, which is a reason this paper is in Nature.