I only use Windows Forms for legacy applications.
As for the official statement, here is the InfoQ overview of BUILD 2014.
https://www.infoq.com/news/2014/04/WPF-QA
"Windows Forms is continuing to be supported, but in maintenance mode. They will fix bugs as they are discovered, but new functionality is off the table. Oh, they stress that it isn’t called “WinForms”."
As I don't have time to search for the video on Channel 9.
The Roadmap for WPF
https://blogs.msdn.microsoft.com/dotnet/2014/11/12/the-roadm...
Removing WinForms will disenfranchise a large group of developers, that for one reason or another, it could just be stubbornness, won't switch. Microsoft will sooner kill of WPF than WinForms, to not lose those developers. At least that's my belief.
But we're talking for desktop applications only.