Its less about immedoate profit and more about pumping up gamepass numbers under one umbrella for investors to see a large number increase. Its part of the reason why Xbox Live Gold has been rebranded into Gamepass Core. Microsoft supposedly is under their sub projection (despite having about 40M subs) and trying to pump the numbers as much as possible.

Overwatch makes no sense given its a feee game. Unless your implying gamepass pays for the battlepass, as the game moving to gamepass would be a detriment on console as it does not require gamepass core to play (as its free)