Paradox says this is the “first step” on their long-term goal to tell the story of “every nation” in WW2. That means you’ll be getting specific alternate history paths (like the one that can take France Communist, or make the US go Fascist) for those countries, along with leader portraits, and appropriate wartime technologies. Together for Victory is going to add National Focus trees for Australia, Canada, New Zealand, South Africa and the British Raj in India. Paradox has announced a first expansion for Hearts of Iron IV, which will primarily focus on Commonwealth nations subject (at the time) to the British crown.