Well, this is certainly exciting. Time for some speculation based on very little:
1. It's CoH3. IGN said it's a "highly anticipated new game", and it's far too late to be releasing DLC for CoH2 (UKF was nearly 6 years ago).
2. "July 13th". On that day in 1943, the German Kursk Offensive was ended (which would make an interesting transition from CoH2). In 1944 the allied raid on Symi began (from Wiki), but that was in eastern Greece, which isn't visible on the map. It's also right in the middle of the Allied invasion of Sicily (July 9th - 17th, 1943), which was right at the start of the Italian Campaign.
3. The video footage we've seen so far (or at least, that I've seen) has mentioned North Africa, Montgomery (UK) , Rommel (Ger), Italian, US and Canadian forces. It has also mentioned Dakar (Senegal), which while it was involved in WW2, isn't on the map we're looking at. As a result, I don't think the footage is covering events that will be in the game, but is instead a 'prelude' to the invasion of Italy, which will end up being the focus of the game.
4. The focus of the map (in the video) seem to be on southern Italy. The location of the timer is actually interesting, as it's covering both Tunisia and Algeria, which were both large theaters in the Africa Campaign. To me that indicates we won't actually be playing there. Additionally, the edges of northern Italy are far too close to the top of the screen, which also takes focus away from it. Based on Wiki's
Atlas of the world battle fronts map (scroll down slightly), only the areas up until July or September 1944 are really part of the focal point, so I'm guessing the game "ends" in July-Sept 1944. This would match the Allies advance towards the "Gothic Line", and their halt in August 1944 when 'Operation Olive' (late Aug 1944) didn't succeed.
TL;DR - CoH3, Italian Campaign, July 1943 to Sept 1944.