State of Decay 2 (opens in new tab) has been a Microsoft Store exclusive since it launched in 2018, but will be arriving on Steam on March 13. When it does it'll be the Juggernaut Edition (opens in new tab), a significantly expanded version of the original (and the Microsoft Store version will also be upgraded).
New in the Juggernaut Edition are an extra open-world map called Providence Ridge, an improved post-tutorial experience to introduce the mechanics, a new category of heavy melee weapons, various graphical improvements, more music, and some bug fixes. It'll also come with the Independence Pack, Daybreak Pack, and Heartland DLC for free.
Those who already bought the DLC separately will receive "some exclusive in-game gifts that won’t be available anywhere else" on launch day as detailed on the State of Decay blog (opens in new tab).