Some of the UI apps perhaps, but if you ripped out win32, I don't think you'd have a very usable machine left to log on to?
Non-sandboxed applications and services are not a sustainable strategy anymore.
WPF was XAML v1. Silverlight was XAML v2. UWP has XAML v3. Your skills are still applicable.
You can also now use it with both native C++ and C# thanks to WinRT.