So Apperently... If you buy CODIW/CODMWR from Windows Store, you cannot play with anyone who bought it on another marketplace such as Steam according to Neogaf...
The Fuck is this nonsense? If this is true, it is truly LOLz worthy
http://www.neogaf.com/forum/showthread.php?t=1306855
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850