No, I didn't say it was easy to hear north of 22 kHz, but an anti aliasing filter causes ringing artifacts that will occur not only above, but also in the audible band, i.e. far south of 20 kHz. Steeper the cut-off slope of the filter, more severe these artifacts. It is possible to reduce these artifacts, or make them less noticeable in pure terms of human audibility by building a better filter. However, to also make them, in every listening scenario that makes sense, perfectly inaudible, a higher than 44.1 kHz sampling frequency is required. Due to a combination of both modern tech and practical limitations, nowadays 192 kHz sampling frequency can be a very reasonable choice for playback of PCM files. Nevertheless, there are a lot of ADCs and DACs out there that are advertised as 192 kHz, but sound worse operating at 192 kHz than some of the ones that don't support 192 kHz operating at 96 kHz. Further, a bit depth over 16 is not always pointless for music playback because a live symphony orchestra can create peaks of 120 dB SPL at listening position so, attempting to accurately reproduce this, the noise floor of 16-bit PCM can become audible.
I don't listen to much classical music, although I quite like much of it, but if there is any benefit to be had from more bit depth, classical music is certainly the context in which that benefit is most likely to be realized. In the end the benefits of "HD,"(if any) recordings are mooted for me by the fact that very little of the music I listen to is even available in an HD format. Even aside from the question of the audibility of the difference, the population of people willing to spend the kind of folding necessary to buy the equipment (even with the most golden of ears) required is so small that I don't see the selection of HD music broadening much anytime soon. I'm sure, however, that the purveyors of HD music will not warn people with an Iphone and buds that they are wasting their money. "Are you crazy? I'm not spending that much money on earphones. That's how much my phone cost!"