It's going to be after the next dlc . Can you imagine the rage if it were to c9me out soon and the only people who can run it are the people who glitched the throne raids .
I don't see any reason why devs would need to wait that long to release it. It will probably drop sometime before next DLC (hopefully), when most people are geared up with atleast item lvl 100-drops, which will be soon enough. The glitchers can have those 101-pieces whenever next SM drops, it's not like that little stat-bump will give them any advantages in there. If they don't know what they're doing, they're going down anyway.
I have heard similar. Though nothing official (to my knowledge) and not necessarily Specifically FOS 3. Though still Fortress of Solitude. Obviously Sunstone Matrix (FOS3) is the most Logical, since it is the arena style raid. Which is how SM is set up.