The Windows 10 version of Infinite Warfare apparently doesn't have crossplay with other PC versions of the game (like Steam).
Uh oh! Just ahead of Call of Duty: Infinite Warfare's release date, a rather upsetting piece of information has been discovered regarding the Windows 10 version of the game. Apparently, the Windows store version of the game does not feature crossplay with "other PC platforms." That means if you buy the game on the Windows store, and your buddy buys it on Steam, you won't be able to play together.
Can I play Call of Duty: Infinite Warfare or Call of Duty: Modern Warfare Remastered for Windows 10 on Windows Store with my friends that are playing on another PC platform?
No, you can only play these titles with other users of Windows 10 on Windows Store.
That's... a rather big deal. Given that Steam is the dominant platform on PC, it means that those poor souls who buy the game on the Windows Store will be trapped with a fairly miniscule playerbase.
So maybe don't buy the game on the Windows Store right now. We've followed up with Activision to see exactly why this is the case, and if there are any plans to reverse the policy.