Is Schoeps a fringe dweller too? No...If you leave the fringe dwellers like earthworks and go to the big end of town whose mics are used in almost every studio worldwide, Neumann, you will see that their mics are specified at 20-20kHz -- even the ones specifically for recording high notes or percussion.
There is nothing there to suggest a benefit from recording above 20 kHz. Yes, instruments produce energy above 20kHz (you can't call it music, because we can't hear it: it is just waste energy). Yes, the paper correctly notes that, "...overtones above 20kHz contribute to the sound quality, or timbre, of sound that we hear or perceive." But the president of earthworks is mistaken if he thinks that a mic that cuts off at 20kHz won't pick up all the audible contribution of those overtones and their interactions. It will. And so will a 44khz sampling rate.