[WindowsCentral.com]

Now we have an answer.
What you need to know

[LIST][*]Microsoft has acquired a lot of studios in recent years.[*]A lot of first-party games like The Outer Worlds are also coming to Nintendo Switch and PlayStation 4.[*]The company has "no plans" to bring additional first-party titles to other consoles.[*]Existing commitments like Minecraft will still be supported.[/LIST]
Over the past few years, Microsoft has acquired a lot of studios in order to boost its first-party lineup. However, as is the case with any acquisition, past commitments have to be honored. Titles like Pillars of Eternity II: Deadfire, The Outer Worlds, and others are still coming to Nintendo Switch and PlayStation 4 alongside Xbox One.

Full story from the WindowsCentral blog...