User blog comment:Argorrath/Call of Duty: Ghosts Devastation Achievements revealed/@comment-1187559-20140402080549/@comment-1187559-20140402165210

Not forcing you to do it would be by making them add them as Easter Eggs and not doing much more. But the fact is they've added them to all the maps, and linked them with an achievement and a challenge. So while they're not directly forcing you to do it, they're still heavily influencing you.