So, during the Die Rise opening cutscene, Russman dies, and Stuhlinger, Marlton, and Misty are overrun, and presumably die as well. Shortly after, Richtofen turns back the clock in order to give them another shot at completing Richtofen's goal. The way I interpreted this was that the characters actually do die at the end of every game, considering that's the only way the game can end, and Richtofen, or previously Samantha, just resurrected them because they had not completed their goal.
[tab][/tab]So, here's my theory: Dempsey, Takeo, Nikolai, and Samantha inside Richtofen's body, are dead. Why? Because Richtofen didn't need them anymore, and he knew that they were more than capable of bringing him down. Therefore, there was no reason for him to bring them back.