Obviously, the addition of Kevin Spacey as the main villain for AW helped create some buzz, whether or not that actually made the game better. Do you want more high-profile actors in CoD campaigns? Does it even matter?
If I recall correctly, Black Ops 2 had Jimmy Kimmel in some cutscenes, but very brief appearances. I really think that they should include more celebrities, especially actors who play well, because as we all know, they have an enormous budget, so they could afford it.
Considering how they got Snoop Dogg to act as an announcer in Ghosts, I'm honestly surprised that we haven't seen more high-profile actors for the campaign. I would love to see more Hollywood stars make appearances in videogames including Advanced Warfare.
I think that it adds to the game a bit if you can identify the actor. I also noticed John Malkovich in Advanced Warfare. I believe there were a couple more famous folks I can't remember right off the top of my head....
Star power can't really hurt the games after all. The more high-profile actors and singers that add content to CoD games, the more I think we'll see even bigger stars start to follow suit.