It seems things aren't all rosy between CodeWeavers and DXVK, as developer Henri Verbeet has written into the Wine Development mailing list to give more details.
The developers working on Wine seem to be going their own way with their Vulkan plans and most thought this was due to DXVK being written in C++, a different license and so on. Apparently, that's not the main issue as Verbeet notes and they didn't pull any punches:
In February 2018, we reached out to Philip Rebohle—the author of DXVK—to start a conversation around whether there were any areas we could cooperate on. One obvious area was the vkd3d shader compiler, which translates Direct3D shader byte code to SPIR-V (much like DXVK has to do), but there would have been other possibilities, like sharing the DXGI implementation, or using a scheme like vkd3d where Wine's d3d11 could have optionally loaded DXVK as a regular shared library. That e-mail went unanswered. Now, I appreciate that different people have different ideas about what's acceptable and what isn't, but personally I think that's extremely rude and uncivilised.
Nevertheless, e-mail gets lost sometimes, sometimes people are busy, everyone gets a second chance. So a few months later, since I was organising WineConf 2018, I sent Philip a personal invitation to attend WineConf, and perhaps discuss things there. That invitation went unanswered too, at which point I was pretty much done with DXVK.
It is my understanding that since then both Jeremy White and CodeWeavers' partners at Valve have tried reaching out to Philip on the subject, but evidently with little success.
Personally, this all feels like it's getting a little too heated for me. Still, it shows that there's clearly some communication issues that need to be solved between all parties involved for the better of us all who use Wine, DXVK and so on.
Hopefully the situation can be resolved in an amicable way, calling someone out in such a way doesn't seem particularly fair though. I've picked up on emails months after they were sent before, it's very common when you're busy and working alone. I did speak to Philip Rebohle after this, who said they would rather stay out of "unnecessary drama in public".
The good news, is that they are working on an official wined3d Vulkan backend going by a codename of Damavand which will be interesting to see.
You can see the mailing list entry here.