Since October 2016 there is radio silence on the actual state of C++/WinRT, including the status of feature parity with C++/CX for XAML, Blend and creation of UWP components.
VS 2017 already had two releases since those presentations.
The only Microsoft talk at CppCon 2017 are about VS Code support for C++ and ANSI C++ compliance, nothing relevant to actual Windows 10 application development.
Any long time Windows developer is recognising the signs that UWP is turning into what Longhorn aspired to be, just remains to be seen how willing Microsoft is to keep pushing it.
See the talks at CppCon 2016:
> https://channel9.msdn.com/Events/CPP/CppCon-2016