If Sony is really that dependent on a Third-Party Game, they've failed. It's all about the loss of profits for their shareholders, nothing more, nothing less. COD has reached a level of influence held by very few. Sony should be scared shitless. They got destroyed in Japan and are starting to lose ground and mindshare in North America. Even though COD is a big deal, there are plenty of games Microsoft doesn't own, pretty hard to prevent a deal based on 1 game or franchise, which might run its course (eventually). Gamers are fickle, what's great last year, can flop the following.
COD though has been going a long time and can survive a flop. It's already shown some significant signs of resilience to fading. In video games we have seen genres rise, peak and then fall into obscurity which has in a large part been driven by the technology. Games that in the past were really popular such as the single screen shooter Space Invader types or the single grid Pacman types have now largely run their course and have been demoted to minigames within much larger games or evolved into something quite different from where they started. But there comes a point like with any other type or products where maturity is reached and a status quo is settled upon. Gaming could be reaching that point perhaps?
Look at other areas where that status quo is already reached. Cars for example in the early years different manufacturers used wildly different methods for doing the same things but eventually we settled on a set of universal rules governing all cars. We think of the Model T Ford as being the first mass produced car and setting the template for the motor industry to follow but just have a look how you actually controlled the thing, Google it and watch some videos!
Those three pedals on the floor are for the clutch, brake, and gas, right? Well, no. The left-most pedal would be low and high gear, while the brake is the pedal all the way on the right.
Think about even more universal things such as clothing, writing or language. We can't go so far back to find evidence of the very early steps of these things but looking back to the history that we do have documented evidence for we see that they did things in odd, less than ideal ways using our current understanding until they evolved to a general status quo. People will have always needed to cover themselves when cold and always needed both verbal and non-verbal ways of communication but it's only through the maturation of those technologies that we eventually reached a status quo.
Lets bring that back to games. We can safely say that kids have always played games and also that one of the earliest games will have been war. Is the FPS the culmination of that game? Possibly... And the biggest most recognised game in that genre currently is COD.
Just because video games IP or entire genres in the past have risen and fallen into obscurity doesn't mean that is destined to always be the case in the future and at some point in time we will probably reach a status quo where an IP becomes evergreen and never fades away.
A few examples of this we already have where a brand name is used as a generic term because it was the most widely and common example at the time that the particular thing became ubiquitous.
hoover, Jetski, jacuzzi, kleenex, bandaid, astroturf, scotch tape, velcro, dumpster, google, walkman, memory stick, photoshop etc.
We are already seeing this happen to some extent in gaming where Mario could become a generic term for platform games, FIFA could become a generic term for football, COD could become a generic term for any game of war. And don't forget that we already have some firmly established generic terms like Roguelike and Metroidvania.