> Also, if you compare the sample code in the post with a sample of Vulkan code, I think it will be clear that a literal "WebVulkan" is a road best not traveled.

Are you sure? Don't forget about WebAssembly… Just as Emscripten currently exposes the original OpenGL ES API as a wrapper for WebGL, for the sake of porting existing C/C++ code that uses it, in the future there will be a desire to port Vulkan renderers to the web. That will be easier if the browser API is based on Vulkan; otherwise you'll end up with a shim on top of a shim. Also, the same arguments about developer familiarity that led to WebGL being designed as it is could apply just as well to Vulkan - albeit somewhat more speculatively, given Vulkan's newness.