I agree with what the above people have said. They could do a series of EPs called something like "The Vision of Michael Jackson: [insert album or era]", and have demos for each original track as well as a few outtakes and unfinished tracks, and some commentary at the end with MJ's collaborators like they did with Thriller 25. That way we can see into MJ's creative process, especially Invincible and onwards, where it seems like he had so many ideas but none of them coming to fruition before he died. We could also in theory get a look at the evolution of certain songs (i.e. "Cheater", which was worked on three times between 1985 and 2009, with each version probably being a massive overhaul).
EDIT: Another idea that came to me just now is that they could release EPs with different versions of tracks. Take "Cheater" for example again. They could have a remixed contemporized version, then the original Bad era version, then the Invincible era version, and then the one worked on around 2009. Also gives us a view into his process and what direction he was taking the song with each revision.
