I think we've all kinda felt like Halo has been the XBox flagship since day one.  But, once this Activision deal closes, they'll own Call of Duty - a much more popular IP.  Does that make CoD the new top dog?  

I think it does.  And, as a Halo fan since launch day in 2001, it makes me a little sad.  

I suppose we can't know for sure because we don't know for sure that CoD will become XB exclusive. But, assuming it does......

Idk if it be the flagship franchise but certainly one of them. Least more so than Halo has been post 360 era.

that would be embarrassing if it is

Call of Duty is Microsoft's biggest IP including Minecraft.

Halo will always be the Xbox flagship title.
Also MS own the monopoly of FPS games.
They need to do some heavy cross overs. Halo in CoD etc

Well it's one of their biggest franchises now.

Halo and COD are....well it's actually interesting. They could arguably be seen as different enough, though it might become a case where they are given alternating release periods. Like when Halo releases a mainline game COD takes the year off.

CoD needs to skip a year here and there so that their development teams can have 4 years per title rather than 3.  I think they're gonna have to do that at some point, at least once, even if they don't do it every cycle.  

Ok, something like this.

1. Call of Duty
2. World of Warcraft
3. Minecraft
4. Candy Crush
5. Elder Scrolls
6. Diablo
7. Overwatch
8. Halo
9. Forza
10. Sea of Thieves