TL,DR: Who the hell knows. No idea. Why can't we go to the Plaguelands or Mars? Where I'm sure the Cabal would be interested in SIVA. People would bitch about it being recycled content, but it would be a valid reason for it to be around. That's unless the Cabal decided to slam The Exclusion Zone with Photos. I can see that being a reason for the Rasputin DLC. Him telling us Cabal are trying to get their hands on SIVA. Why not? We got the annoying ass Taken. Why not throw SIVA-infused Cabal at us? And we see Rasputins Frames that he used against the Iron Lords that haven't been seen before nor since then. Which I have a feeling are Proto-Exos. More likely them just being giant RedJack Frames, since that's all the bosses are right?...... Just bigger versions of existing enemies. We got a giant Hobgoblin, a giant Vandal, a giant Shrieker, giant Cabal, giant Minos, giant Servitors, giant Captains, a giant Harpy, giant Ogres, giant Knights, and giant Hydras..........why not throw in some giant frkn Thralls, Dregs, and Goblins. Because why not make unique looking bosses when we can just make giant versions of the current, change a few details, and boom a totally "new" enemy is born. Guess this turned more into a mini-rant as I typed...... eh screw it. Edit: Giant Shanks too. Edit 2: Expect a giant Psion soon too I guess.