Call of Duty is literally the fourth biggest franchise in all of gaming, after Mario, Tetris, and Pokemon. By itself, the merger is big enough to warrant investigation by regulator bodies, and that's before you factor in all the other IPs which Microsoft would acquire with the merger on top of that, like Diablo, Overwatch, Tony Hawk, Spyro, Crash Bandicoot, etc etc.

A single Call of Duty game has outsold the lifetime sales of any franchise on OP's list. A single Call of Duty game has outsold the lifetime sales of the entire original Halo trilogy.

Pretending it's just another game series which can be easily replaced is fucking asinine.