It's not hard to figure out.
Because this deal was made several years ago, when MS was in a less precarious position and PS5 and XS sales were much closer. The game was announced in January 2021. The next Xbox and PS consoles had come out and were selling out. At the time, few expected Xbox to win the generation, but expected them to be much more competitive now that they owned Bethesda. Nobody expected Xbox to completely shit the bed at that time.
It's also now well known that Disney exclusives require specific sales number that MS could have easily sold as doable at the time of the negotiation.
Again, not hard to figure out.