Bungie set the terms of that deal.. Not Sony.
The terms is that SIE bought 100% of Bungie and all their current and future IPs, so that Bungie became a fully owned and controlled SIE subsidiary that reports to Jim Ryan. So they will do whatever Jimbo tells them to do or if not they will be fired and won't be able to go away with the Bungie company or IPs because Sony now owns them, not Bungie or the Bungie employees.
For now, if they don't change their mind Jimbo will let them to continue publishing full multiplatform using their own Bungie publishing label to differentiate it from the new PS only games published by PlayStation Studios publishing label. Or at least it's what they said until now.
If MS decides to make exclusive CoD and who knows if other shooters like Doom, Overwatch, etc. maybe Jimbo changes his mind and makes the Bungie games exclusive or at least don't release them on Xbox.
What is Jim giving Phil in exchange for keeping COD on their competing system for three extra years beyond the prior agreement? What has Jim given in return for keeping Minecraft on the platform? What has Jim given back for Phil honoring the exclusivity agreements in place with studios they acquired? Corporations break contracts all the time but Phil has fulfilled every one and intends to not just fulfill this current contract but allow Jim to continue having COD for three years beyond that.
Seems like charity from Microsoft and Jimbo seems to think he's entitled to it.
Jim gives Phil 70% of the revenue made by CoD and Minecraft on PS and gets for himself 30%. PS is the top grossing platform for at least many AAA IPs.
We know CoD made up to around $3B/year, being around $1B of that CoD mobile. So if Phil makes CoD console exclusive then MS would stop earning maybe around $1B per year that is generated on PS.
If ABK makes let's say $1B/year with CoD on PS, then Sony makes around $428M/year of the around $25B/year that SIE makes. If CoD sells let's say 10M games/year on PS where there are like 300M games sold/year on PS. The percentage of both things are smaller than the multi year growth that SIE revenue has.
If CoD leaves PS, MS would lose more than PS and it wouldn't be something really that big for PS/SIE because with the growth they have they'd quickly compensate it. The difference between making CoD exclusive or not wouldn't make Xbox and GP grow a lot because many players already have both consoles or have PS and gaming PC.
There's little charity.