Multiplayer took priority.
There will be no zombies mode in Call of Duty: Black Ops Declassified, Activision Blogger Dan Amrich has confirmed.
"'Will it have Zombies?' That's the top question I've gotten about the PlayStation Vita-exclusive Call of Duty: Black Ops Declassified since it was announced. Unfortunately the official answer is no, but for what strikes me as a decent reason: Multiplayer took priority," explained Amrich.
He added: "That makes sense to me. This is the first Call of Duty game on Vita, and it needs to deliver on its core strengths — arguably, multiplayer gaming with twin-stick controls in a portable format. That's the core experience, and that simply needs to come first. There's always a list of things you want to do and things you need to do, and at the end of the day, realistic goals are the ones that people actually attain."
The game will, however, offer a Hostiles Mode, in which players must defeat waves of enemies – only they won't be zombies.
Black Ops Declassified is without a confirmed release date, but it's assumed the game will arrive on November 13 alongside Black Ops II.