@Vorontsov zombies are confirmed (obvs).
@FMPONE personally I'd rather get a proper campaign done right than scattering left and right with no sense of continuity.
I don't get the sense they are going so much back to COD1 as that (in the featurette they talk about visiting every real location the game takes place)… but I might be wrong.
Still tho, with the length of campaigns shortening every time, I struggle to see how they could do more than one front with this production value.