According to staff at Cloud Imperium Games, the space combat and adventure game Star Citizen is going to exclusively use the Vulkan API in the future. They go on to state that DX12 and Vulkan have the same feature set and similar performance gains, but Vulkan can be ported to more OS's whereas using DX12 would limit them to only Windows 10. So it is their intention to drop DX12 in favor of strictly Vulkan support. DX11 isn't even a consideration for the final product.
I found it interesting that the developers find that, "95% of the work for these APIs is to change the paradigm of the rendering pipeline, which is the same for both APIs." So effectively there really isn't much difference between the competing APIs. He does leave the DX12 door slightly ajar by stating that, "DX12 would only be considered if we found it gave us a specific and substantial advantage over Vulkan." Even if you're not interested in space combat and exploration, it's always fascinating to read how developers think and why certain choices are made. I would think that strictly using the Vulkan API should save on platform port costs also.
I know that it was stated that Star Citizen wouldn't come to consoles, but you never say never in the games industry; especially when millions of dollars are thrown at projects to become exclusives. Of course all of this hinges on the game actually conquering it's feature creep and launching in a reasonable time.
Years ago we stated our intention to support DX12, but since the introduction of Vulkan which has the same feature set and performance advantages this seemed a much more logical rendering API to use as it doesn't force our users to upgrade to Windows 10 and opens the door for a single graphics API that could be used on all Windows 7, 8, 10 & Linux.