To argue in this, would it? Could've sworn one of the principle reasons for the M&A since the start, was King and the mobile games developed under them and Activision/Blizzard, and how they'd fit into a hole that Microsoft actually does not have filled: Mobile Games.
Back to CoD, One of the big things that has been talked about, especially in regards to the future; is on the subject of accessibility and platforming with the deals in place. As it stands, Nintendo co-signed and agreed with both Microsoft and Activision/Blizzard on a 10 year deal beginning with the next CoD to ensure that particular franchise goes on whatever is Nintendo's platform (be that Switch, or the impending Switch 2). Additionally; measures have been placed to where if it would go through, that they'd honor all agreements currently made with Sony (like what was done with Bethesda for Deathloop and Ghost Wire [The former being a fantastic FPS title]).
If Microsoft is willing to go Mohjang on the biggest FPS franchise, why couldn't other franchises in that deal?
