User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-82.12.192.38-20130803135719/@comment-3123696-20130803163030

Two things wrong with that.

Richtofen is a zombies so he can't be playable unless you did Maxis' steps (which suck btw, guy's an asshole), and if he's playable, he'll be inside Stu's body.

Now, Samantha is on Richtofen's body, so he can't be playable technically with the old crew.