In the living towers there is a "premier tower" which seems like it will last a week. This weeks is where you play as Goro. I am assuming next week is gonna be a classic MK1 tower where its all MK1 characters since everyone but Shang is in the game.
It's one of the MK1 premier towers.
Ed Boon said that the second tower will be the MK1 tower, and finishing it will get you some sweet icons for your tag. Check it out here.