This is the first bit of information we have on the game’s planned DLC, which will comprise of 3 single-player add-ons. The new character seems to be a part of the earliest DLC addition. The work listed can be seen directly below:
The official website was/is already teasing “New Stories. New Characters. New Weapons”, but this is still a bit surprising considering the enormous number of hours that went into getting Elizabeth’s A.I. “working”.