Why no Conservative Rasterization in Vulkan?

As far as I can tell http://vulkan.gpuinfo.org/listfeatures.php Vulkan doesn’t support conservative rasterization curently. It’s a very useful feature and both OpenGL https://www.opengl.org/registry/specs/NV/conservative_raster.txt and DX12 have it https://msdn.microsoft.com/en-us/library/windows/desktop/dn914594(v=vs.85).aspx .
Does Vulkan have ROV-like functionality? https://msdn.microsoft.com/en-us/library/windows/desktop/dn914601(v=vs.85).aspx

No, it does not.

Pointing to a proprietary NVIDIA extension and then saying that “OpenGL has it” is rather wrongheaded. NVIDIA has it; nobody else does.

Is there some reason you felt the need to ask this question yet again?

Oh sorry I forgot about fragment shader interlock regarding conservative raster well even if only Nvidia has OpenGL extension DirectX12 standardized it so Vulkan should be able to expose this hardware functionality.

At the current moment, conservative rasterisation is only supported by one vendor. Knowing NV, they will expose it as an extension right after their driver will reach stable status. It only makes sense to add this into the official specification when\if at least one more IHV will decide to implement this feature. This is how it always worked with OpenGL and OpenCL.