I believe the licensing agreement dictates not only a specific maximum number of copies, but also a time limit, whichever comes first. Hence, certain sets will go out of print having sold fewer than the maximum allowed.
I can't confirm it, but it makes sense, as the rest of the band is Fred Katz, Paul Horn, John Pisano (listed as "Asano"), & Jimmy Bond. And, of course, Chico's given name is Foreststorn Hamilton.
I'm speculating here, but perhaps the terms of the deal included retitling the material, so that Fantasy did not create competition with its own releases. Perhaps Fantasy wanted to conceal the source of the material for some reason.