Do you have a link to this AES study and the test procedures and also the type of people that took part (were they used to listening for such differences in ideal conditions?)?Let's pause at step 1. Let's assume the M-Scaler does a perfect job in remediating the potential artifacts of a 24kHz brick wall filter. Again assume this brings the sound quality of the audible spectrum of a 48 kHz recording to that of an original 192khz recording.
Now, in general, how big is the difference in sound quality between a 48kHz and 192kHz recording (and I mean audible difference)? That difference is more than the theoretic maximum of what the M-Scaler can do for you (as it still doesn't restore the ultrasonic spectrum).
What if the latest study published by the AES showed most people can't even hear a difference between CD and high res. (hundreds of people involved in the test, with less than 2 able to hear a difference)? Than how much benefit can these people expect from an M-Scaler?
(Now sit back and wait for someone to argue the high res study failed because most people don't have a Chord DAC )