You can build Tizen apps in .Net now I imagine they're working to improve compatibility across all Tizen devices. Samsung is also now a member of the .Net foundation
https://www.tizen.org/blogs/dh0922/2016/tizen-.net-developer...
https://www.tizen.org/blogs/dh0922/2016/tizen-.net-developer...
They already went through Meego APIs, replaced by Bada OS C++ APIs, replaced by C and Enlightenment APIs, alongside HTML5 apps.
As a developer I would be weary to invest any resources in so unstable OS design.