Microsoft is rolling out an update for Insiders in the Release Preview ring for Windows 10 that rebrands the built-in Windows Store app as "Microsoft Store" along with changing its icon in Start and on the Taskbar.
The rebrand is currently in testing with Insiders, and outside of the rebrand itself nothing else appears to have changed in the app. Microsoft may be planning to start selling more than just digital content in the built-in Windows 10 Store app, hence its rebrand to "Microsoft Store."
Microsoft already has an online Store which it calls "Microsoft Store" too, where it sells software and hardware from first and third-party partners. It wouldn't be surprising to see Microsoft begin moving that content in to the new Microsoft Store app too at some point.
For now though, the only thing that appears to have changed is the apps name and icon. Microsoft is yet to make an official announcement about its plans with the new "Microsoft Store," and the update could just be testing the waters to see how people react. I personally am very excited about this change. What do you think?
Thanks for the tip, @Christoph_fer!