I think that you misunderstood me. One of the reasons that people claim that recordings having a sampling rate above 44.1kHz are needed is that some people can perceive energy/sound above the 20khz threshold and by having a recording with only frequencies above 20kHz would show that this is either true or false. My guess is that no human will be able to hear these frequencies, which is not something the people pushing high resolution would like to have proved.
Next up: the myth about higher sampling rates producing smoother, i.e. more accurate, sine waves at all frequencies but especially at or near 20kHz. Oh wait that one's probably been bandied about in the High-end Audio Forum section. I forgot that this is the Sound Science section.
My argument against this test is that it may not be representative of real-world acoustic content. For instance you can you high frequency sine waves all you want, this testing may be limited in use. Basically, it's a similar type of argument that we are not sensitive to the specific phase of the sine wave, but it doesn't mean that phase response is not important.