User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-25496444-20130731143518/@comment-176.253.248.29-20130731231441

Might not even be from a diary, he could of just wrote it on a piece of paper! Hell, might not even be a he... There is absolutely no solid evidence any of this is going to play a part in the next map so like MLG's pic says, no-one can claim it is definately from something.