Correct, the option. It's nice having options isn't it.They also introduced an option where you can select to only get matchmaking with people using the same input type.
Which reinforces why it's never been acceptable to use a KB+M on console.
I own a gaming PC, I have used both extensively and I don't want to see them making it compatible in any FPS games on a console. Other games is fine. If you are going to put it into FPS then KB+M should be separate matchmaking as mandatory not opt into it. Allowing them to play against controller users is like letting formula 1 drivers use bigger engines or lighter cars, etc. It gives you an advantage over a controller. That doesn't mean you will be a god if you use KB+M game skill is far more important therefore better players will be able to exploit that advantage more and make it bigger than those that are crap who will barely see any improvement.
Surely no different than having the option of using a wheel in a racing game.