Good question man... That rerelease of TM1999 with a third disc would be amazing to get for sure! They don't seem very interested in releasing old unreleased material unfortunately

They seem much more interested in releasing new music and touring. I would think a part of this is that re-mastering old old music is not cheap, and they haven't pulled in the same direction as a group creatively for more than a decade.

I suspect there are also legal issues, probably. It's hard to know for sure what they own and who owns it. Layzie has been re-releasing Mo Thugs, Faces of Death and put out Lost Archives so we know that he, in one way or another is sitting on a lot of songs. Krayzie posted pictures of old dat tapes dating back to the late 90s on instagram a couple of years ago. That would suggest he also sits on a whole lot of tracks. Also, we know that Johnny J's wife has a say in the Heaven'z Movie re-relase, which was supposed to come out. Bizzy now atleast has the rights to some of that, because he is promoting HM merch on his Website (same with Krayzie and TM).

Idk if Tomika is still in the picture as far as older material from Eternal and AoW, but I would assume Ruthless still hold rights in one way or another. U-Neek also has a whole lot of stuff he has been putting out here and there over the years, but those were mixtapes so idk if he owns it, owns a portion or just has the old files.

Then you have people like Caz, who got a hold of some of their catalogue and started putting out albums. 

To be honest, I think it's still a legal mess they can't figure out.