Pvt. Miller

Theroy of Nacht Der Untoten Spoiler ALERT
Ok so i had a theroy, when the campaign ends you know u got to nacht der untoten but the character u r is unknown and doesnt talk. In the campaign Miller doesnt talk and the FOV is a US marine outfit so is it Miller from the campaign that u r playing? Also in the map Airfield for Multiplayer, the bunkers look like the Nacht Der Untoten one. Let me know about this theroy in the comments.