Microsoft has begun using Project Centennial to add some of its Win32 apps to the Windows Store. First spotted by Twitter user WalkingCat, these apps include WordPad, XPS Viewer, Windows Fax and Scan, and Microsoft Character Map.
Project Centennial - Microsoft's bridge for getting classic desktop apps into the Windows Store - requires the Windows 10 Anniversary Update to work, so don't expect to be able to download these apps any time during the next two months. In fact, at the current time, you can't even download them if you're on the latest Insider build.
Microsoft recently released the Desktop App Converter in preview form, which allows anyone to package a Win32 app as a UWP app; however, it will only run on x86 CPUs. In other words, Centennial apps won't run on your Windows phone.
So when can you download these fresh new UWP apps? Chances are that you won't have to. Most UWP apps that come preinstalled on Windows 10 (Photos, Messaging, etc.) can be uninstalled and if you wish to get them back, there is a Store listing for them. That is likely what these are for.
If you want to check out the Store listings, you can have a look: