I have never seen such communication as being benefitial in normalizing relations much more quickly once the war is over. What does normalize relations much more quickly after war is ironically demonizing the enemy during war. When you make up names for your enemy like Jap or Krout then when the war is over you can separate the actions of the "Japs" or the "Krouts" from the Japanese and German people you meet because even though they are actually the same people, emotionally you can separate them as the enemy and them as the people who now you are trying to normalize relations with.