User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-98.233.126.228-20130802015134/@comment-9010268-20130802202748

It is unconfirmed that the new crew are dead, as the events of round infinity were never confirmed to actually have taken place. And then tere is the whole round infinity doe sot even exist if you side with Maxis, so if you were referring to infinity round I would not place faith in that as of now.