User blog comment:Argorrath/Treyarch releases a BO2 teaser video called "Origins" for DLC 4/@comment-10261308-20130807060053/@comment-5081943-20130807122304

The letters ARE hints to the old crew coming back. Even if it's not actually them writing that, what else could you possibly make from 4 letters written by a German, a Japanese, a Russian and an American? Obvious hint is obvious.