Hello, and welcome! 
When Tizen 2.2 was new, we added support for the platform, but when they updated to 2.3, they removed most of the native APIs we relied upon, and did not release updates for our development devices. With no good way to test the newer version, we abandoned support.
I visited SDC this year and spoke with Tizen developers, they said the API has stabilized, and that they would consider SDL2 support. Since the time that we first added Tizen, we have moved most of our stack to SDL2 on the native side, so if they add SDL2 support then we will be able to inherit Tizen support with little work on our end. Unless someone was motivated to spend the time to write a new platform support layer, I think this is our best bet, while we wait and wish Tizen the best 
Do you use the platform?