The Windows Store is being rebranded to the Microsoft Store to better encompass the new hardware on other items the online site will soon be selling. The good news is that the Windows Insiders on the Release Preview ring are now getting a look at the updated storefront.
The Microsoft Store has been in testing with Xbox Insiders and Windows Insiders for the last couple of weeks, but it appears that a full rollout could be happening soon, perhaps as early as tomorrow's release of the Fall Creators Update. The move is more than just a name change, as Microsoft appears to be bringing all of its hardware, such as Surface laptops and third-party products, into the Store app.
Microsoft's Cortana also now refers to the store by its appropriate moniker, although not all Windows 10 users running the Creators Update can see the new branding and functionality. However, that will likely be fixed will the new update tomorrow. Xbox users got the Fall Update today.