During the Microsoft Build developer conference, it is precisely the Redmond company to let people know that iTunes, and therefore Apple Music, will come in the Windows Store later this year.
The application will support the iPhone and allow you to play music from Apple Music provides the same user experience of the Windows program.
What will change then? Basically, Windows 10 S only support installing applications in the Windows Store. Consequently you can not add programs downloaded by the browser. Who want to buy a product with Windows 10 S will not have iTunes until Apple did not release the virtual shop, which, however, has just promised to do.
As for iTunes, there could also be some cosmetic changes and function less so as to simplify the program and make it lighter and easy to use.