While the official release date for Halo Wars 2 is February 21, people who purchase the $80 Ultimate Edition or pick up the $350 Xbox One S Halo Wars 2 bundle can start playing the full version of the game right now.
Halo Wars 2 is available for Xbox One and PC as an Xbox Play Anywhere tittle. So in essence, buying the game digitally on one platform will get you a free copy of the game on the other. Additionally, saves and achievements are also transported between platforms.
The physical PC edition of Halo Wars 2 has been canceled for the United States, though it will still be available in Europe.