I know the Rhoads documentary crew has gotten a hold of some stuff that they claimed was never before seen. But they said the rights hadn't been secured yet. So maybe the price tag was too high for them, but worth it to Osbourne.
Although I have my suspicions it's stuff thats been available through unofficial tapes. Still it might be from the original source material, and not a 9th generation dub. Looking forward to it for sure.