The memory of the Soviet Union's victory over Nazi Germany in the Great Patriotic war never faded, behind the Iron Curtain. If anything, they down played the role of the Western Allies inside the Soviet Union. After the Cold War started, Hollywood ignored the Soviet's role in WWII. However, people who were really interested in World War II could find out about the Eastern Front and the sheer enormity of the role of the Soviet Union in defeating Nazi Germany.
In the early 1950s, when Senator Joe McCarthy was whipping up the Red Scare, the quasi socialists in Hollywood, were not going to sacrifice their own careers by making a movie about the huge tank battle at Kursk that was of a similar high quality to the 1962 movie "The Longest Day". The fact that the Communists were perceived as the "bad guys" meant the Soviet Union had to fall apart. before Hollywood would make a big budget movie about the battle of Stalingrad. More specialized documentaries, like "The World at War" in the 1970s or the ones shown on the History Channel (back when it was really a History channel) did cover the Soviet Union's role in World War II. However, because of the Cold War, these films were not as widely seen as a big budget Hollywood movie, like the 1970 movie "Patton".