With the Call of Duty: Modern Warfare Open Alpha on PlayStation 4, Infinity Ward enabled the ability for players to connect their keyboard and mouse and play Call of Duty: Modern Warfare through the Alpha.
For this Alpha, it does appears that keyboard/mouse and controller players are in mixed lobbies for testing as it is just an Alpha on platform, but Infinity Ward has not explicitly stated this. Infinity Ward confirmed that keyboard and mouse players can party up with controller players in the Alpha.
The studio also confirmed on Reddit that they plan to add additional keyboard and mouse settings, including sensitivity options, to Call of Duty: Modern Warfare across platforms — allowing players to use whatever input device they would like on platforms. The additional settings will be available in the Beta as well.
Not all of the settings are in just yet. You’ll have them for beta.
With Cross Play in Call of Duty: Modern Warfare, players can play with their friends on any platform through matchmaking. The studio did state that at launch the matchmaking will be input based allowing controllers to play against controllers and KBM to play against KBM. The lobbies in Call of Duty: Modern Warfare also showcase an icon next to player’s names indicating their input device.