If 4 million people buy a copy of Call of Duty on Xbox for $69.99, that would represent $280 million in revenue
If 2 million new people subscribe to Game Pass for Consoles at US$10.99 to play Call of Duty and stay on the service for a year, this represents revenue of US$264 million. In the case of Xbox Game Pass Ultimate at US$ 16.99 it would be US$ 407 million dollars (80% of GP subscriptions).
Only for new subscribers, apart from regular subscribers.
If you keep these 2 million subscribers for the second year (the Call of Duty franchise is annual) it would be a total of Half a Billion Dollars ($528 million) on Game Pass Consoles and $814 Million for Game Pass Ultimate
But why stop at 2 years? There are people who stay with Game Pass for much longer than just two years. In the long term, Game Pass with Call of Duty and other games makes Microsoft much more money than it loses with advance sales of games at $70 dollars.