Who is this store for? Customers or Corporations? If it's customers it's DOA.
Customers don't want anything to do with Microsoft products. Xbox, phone, mixer, explorer, Bing. No one cares. MS = Excel spreadsheet at work. They have to hide the Xbox logo in Minecraft for fear of people deleting the game
I'm sure Outlook is on Windows Store but people still use Steam. MS Word and Outlook is not a draw
You realize that one of the biggest uses of the Apple App Store and Google PlayStore is enterprise right? And they bought ABK specifically for things like Candy Crush and Warzone Mobile.
63 million MAUs on LinkedIn mobile
over 100 million downloads of Outlook Mobile
320 million active users using Microsoft Teams
250 million MAUs for Candy Crush
50 million users on Warzone Mobile
over 100 million users using Microsoft Authenticator