It's just a matter of following the money. A bigger and bigger slice of Microsoft's income is coming from Azure, and an increasing proportion of Azure users are running Linux. This gives them strong incentive to be the business leaders in open source software.

The other increasing slice is services, where they get you to buy stuff from their storefront, or subscribe to their game pass, or office 365, or make personal interactions with Bing and Windows (so they can sell targeted ads). This naturally gives Microsoft the incentive to know everything about you.