Interesting. May be it's "right hand doesn't know what left hand is doing" kind of situation. Some developers there want to advance Vulkan while others are hung on NIH. It's not uncommon in huge companies.

Or may be it's just a longer term effort and they need to keep updating NVN until Vulkan improvements are sufficient to stop doing it.

The Vulkan post mentions this:

> VK_EXT_shader_object represents the culmination of years of work to bring Vulkan developers ever more powerful and easier-to-use ways to manage shaders and state. We’re proud of what we have achieved and can’t wait to see what developers can do with this extension once you get your hands on it.

So it sounds like they've been working on that for a while. They also mention some pending items like ray tracing in that context. In the end, constantly reinventing the wheel is just pointless and wastes resources. So it makes sense for them to focus on Vulkan.