Actually, the source of several of these has been discussed before on PSW... -The Stevie Wonder Superstition, Queen Bohemian Rhapsody, along with several tuens from the Doobie Brothers' and Marvin Gaye apparently all were disseminated via bit torrent sites, or whatever Napster-like tendrils.
I remember postulating my view that -while it can be educational and instructive to examine the multitracks ALONG WITH THE COMPLETED MIX- as an insight to lots of things like balance methods, tricks, and all sorts of other stuff like control room leakage, and how the significant-versus-insignificant balance plays out. -But that it also allows some people to 'play' at having 'power' which is somewhat beyond their entitlement insofar as their experience allows.
The Marvin Gaye, Stevie Wonder etc have been out for several years; this is simply a slight agglomeration and -sadly in my view- just spreads this even further.
For so many of these sessions, the MAGIC was what was happening AT THE TIME, and even the same people wouldn't produce the SAME magic at a later date, so the point of playing with these multitracks, and trying to 'improve' upon original mixes (which I hear CONSTANTLY discussed among the younger breed of 'new' engineers) by using modern tools and available technology (think beat-detective, auto-tune, and their like) would -in most cases- be like trying to 'improve' on the Mona Lisa because we have modern paints which are smoother and easier to work with the brush...
I mean... Imagine how much 'Better' the Beatles would sound with Melodyne and beat-detective.
That's why this ready availability and Wikileak-like 'sharing' crushes our souls, little by little.
Keith