User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-67.169.165.224-20130805104048/@comment-10357065-20130805132653

Dempsy replaced the Mexican when he was captured. I believe that can also be heard in call of the dead. It wouldn't make sense he would be a richtofen replacement if they have the Mexican for some reason