My hearing has passed the point of being able to hear high frequencies, but just because I can't, doesn't mean that others can't.
While there's definitely a lot of evidence that CD is transparent, much of it is public domain and widely read and taken as gospel.
There is also evidence that high resolution audio does make an discernible difference , but it tends to sit in AES papers that cost money, and are not widely read.
Where you have contradictory evidence like that, my view is that you should take the result with the highest positive result, rather than the lowest negative result.
There's also evidence that just because you can't hear anything under 20Hz or over 20kHz, it doesn't mean that a 20 to 20k bandwidth is transparent.
Yes that sounds completely unintuitive, but so far we have all been making the assumption that audibility can be based on audibility of continuous tones.
There was some research at Kyoto University and published in the
Journal of Neurophysiology Volume 83 Issue 6 that concluded that although listeners could NOT detect any sounds that were high-pass-filtered at 22kHz, they COULD tell the difference between full-range audio, and audio that had been low-pass filtered at 22kHz.