They abandoned a lot of projects related to BO2. There was the old map loading screens within the data files that were presumably planned for bringing the old maps back.
There was also the reveal of power on the Green Run map selection screen. It can be seen in the PC files uncovered, and there was data in the script showing it was going to be used for survival and so was Diner.
Then there was the loading screen for Town that showed it untarnished. Presumably for the hidden game mode 'Meat'.
I am sure there was a lot more things that got abandoned or cut short... like the proper use of the NavCards.