The Saboteur is set in France. During the Second World War. You're fighting Nazis. During the Second World War. But developers Pandemic would like you to know, this isn't a game about the Second World War!
Pandemic's Thomas French says "...we don't even really think of our game as a WWII game, it's the backdrop to our game which gives us arguably the best real world bad guys of all time".
Slightly silly, maybe, but also perfectly understandable from a marketing standpoint. I think people are just...done with the Second World War. We've been hit with too much of it over the past ten years, and even with fancy colour design and boobs, it's hard getting psyched for another game where you're killing Nazis in the 40's.