“Gears 5 is coming to Steam and Microsoft says it’s just the start of a new commitment to making its game offerings better for PC gamers. Xbox boss Phil Spencer wrote an extensive message that sets down several new appeals to the PC gaming crowd, including bringing more games to Steam and setting up a new Xbox Game Pass program that’s curated just for PC players.”

Source

It is also coming with the definitive editions of Age of Empires I, II and III

“We will continue to add to the more than 20 Xbox Game Studios titles on Steam, starting with Gears 5 and all Age of Empires I, II & III: Definitive Editions […]”

If you prefer to buy your games on the Microsoft Store, you will be able to.

And a reminder that Microsoft will enables the sale of Win32 applications.