Your estimates don't consider the impact of those 6 million people subbing to Game Pass, or even half of them doing it, and the increase in MTX spending they would engage in.
10m people on PS buying COD Day 1 is $490 million revenue for Microsoft once Sony's 30% cut is taken out. 6m of them going to Xbox in case of COD removal from PS is now $420 million but MS keeps 100% of that money. A deficit of only $70 million. However, say 3 million of those 6 million decide to get the game through Game Pass, and they're new Game Pass subscribers.
That is now an extra $540 million in GPU revenue thanks to COD, in addition to the $210 million from the other 3 million who don't sub but buy the game. Altogether that is $650 million in total revenue from COD (B2P, inclusion in GP), so MS actually make $160 million more in a COD withdrawal strategy off PlayStation, using the player numbers you gave in your example and assuming that a decent number of them would likely sub to Game Pass thanks to the game and keep their sub to play it online year-round plus whatever other games are in the service.
None of this is plausible since any deal will involve Microsoft guaranteeing long term access to Call of Duty on PlayStation, in a legally binding contract ratified and enforced by the EU.
Your scenario also fails to cover the potential long term damage to the Call of Duty brand if it went exclusive to Xbox. Most users won’t ditch PlayStation, and we know Sony’s been hard at work at multiple GaaS rivals.
After seeing how Halo fell from crazy heights of 1 million + player CCUs to the struggles of Infinite, I doubt there’d be anyone willing to take the risk of having COD suffer a similar fate.
I don't think this was ever in question. no one cares about this.
Sure, they do. If we’re talking about sticking to public statements.