When people talk about OpenGL and things like Vulkan going forward, you inevitably are talking about a media layer such as SDL because you need a context for your GL renderer if you're using older OpenGL, and even with vulkan you need a media layer for things like controller inputs.
In my mind and the minds of many, OpenGL and SDL (and Vulkan and SDL 2.0) are peas in a pod, because they specifically compliment each other. In fact, it's a shame that people are
not talking about SDL with regards to windows UWP scheme because
SDL is a very counter to many of microsoft's claims. SDL 2.0 is a clean break from SDL the same way Vulkan is a clean break from OpenGL, and they've been developed in concert to compliment each other. SDL 2.0's driving feature, in fact, is the concept of "write once, deploy many."
I'm sorry, the reality is if anybody is talking Vulkan, they are also almost assuredly talking SDL 2.0.
The way microsoft ignores the Khronos group and doesn't give SDL the time of day is just another clear example of the practice they'd supposedly abandoned - they are ignoring a popular, open alternative, one that is being reinvented as we speak, to prop up a proprietary solution that is going through the exact same growing pains.