Depends. In F/UC, did they ever announce that Zero/Lancer would be playable? Or did we all just find that out when the game was released?
IIRC, Leysrit, Saber Alter, and Bazete were all announced prior, but i don't remember anything about Z/L.
Maybe itl be the same kind of thing, and well just get a surprise new addition when the game is released.
Of course, correct me if im wrong about any of this.