Yeah, there was literally a Hackernews a few years ago who pretty much said what I said, but unironically: that there was music out there better than you've ever heard, but you'll never hear it because it's only released in print runs as few as one copy, and that copy is owned by a DJ who will never let it be heard again, and that this was by design because a wide listening audience would spoil the goodness of this impeccable music. I can't be arsed to find this comment just now, but I remember reading it.
See also: Prince's Vault (from which I believe his estate is now compiling material to be released).
Here is another example of exclusives from the old soundclash culture.
A dubplate is an acetate disc usually of 10 inches diameter, traditionally used by studios to test recordings prior to mastering for the subsequent pressing of a vinyl record, but pioneered by reggae sound systems as a way to play exclusive music. They would later become an important facet of the jungle/drum and bass, UK garage, grime and dubstep music scenes.
But this phenomenon is real among music purists. There is not irony in the real act of exclusively guarding the sharing of music that is known to put the listener into the state of mind of musical enjoyment unlike anything one has heard before. I would argue that is the a main point of music, and replaying the same sounds at every concert can work but what if the audience had no idea what to really expect? Their minds cannot predict and hence the stimulus hits different. But again, some minds may not want that.
See also: Prince's Vault (from which I believe his estate is now compiling material to be released).