Forced Crossplay

Doesn't Microsoft OWN activision? Why would they not do it in the first place?

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today despite this Marcus

Microsoft is not the developer of modern warfare II, it's Activision. You can share this feedback with them here:
https://support.activision.com/options
Hopefully they can change their mind and give us the option to enable or disable crossplay

ok, so you think you are disadvantaged playing against pc players, what about those on xbox one playing against those on series x, you have better performance, higher frame rates, they better make it so they can also turn off crossplay with series x too and series s as even that has better performance than xbox one but not as good as series x so they should wall all three versions off.

don't say oh it's keyboard and mouse as people use them on consoles too.

Nope, the deal is not closed.
Also, even if they own Activision. Activision is going to be a completely different company.

Like Mojang, Microsoft owns it but they have their own support , webpage, etc

No. Microsoft is in the process of trying to buy Activision. The sale hasn't gone through yet.