Yes, it is just for show. 1945+ and Cold War events/tech were just another marketing gimmick bolted onto a WWII game. But they were never fully implemented or incorporated into the gameplay. Because if a player is somewhat successful during the WWII time frame there would of course never be a cold war.
(Unless the start of WWII is delayed..., have your CW first and then WWII... would be neat to have events for an extended Allied and Axis arms race)
However, it's a waste of time for the DH team to worry about post WWII events, people playing minor countries, or ahistorical play. Yes, these are included as bullet points to sell the game, but the game is really only designed to be played as a major power. Even then, some countries are still goofy or not a challenge.