Microsoft's only choice to move forward is to throw the Win32 baby out with the bathwater [zdnet.com]. And that brings us to the introduction of Windows 10 S.
Windows 10 S is just like the Windows 10 you use now, but the main difference is it can only run apps that have been whitelisted to run in the Windows Store. That means, by and large, existing Win32-based stuff cannot run in Windows 10 S for security reasons.
To bridge the app gap, Microsoft is allowing certain kinds of desktop apps to be "packaged" for use in the Windows Store through a tooling process known as Desktop Bridge [microsoft.com] or Project Centennial.
The good news is that with Project Centennial, many Desktop Win32 apps can be re-purposed and packaged to take advantage of Windows 10's improved security. However, there are apps that will inevitably be left behind because they violate the sandboxing rules [microsoft.com] that are needed to make the technology work in a secure fashion.
"A casualty of those sandboxing rules is Google's Chrome browser. For security reasons, Microsoft is not permitting desktop browsers to be ported to the Store."