While you aren't wrong, i'd argue RayTracing is less important than raw performance. Ray Tracing is a looooong way from being a standard feature. So i'd take the performance benefit, rather than massive performance penalties for an unequal graphical uplift.
And technically with the wrapper, Vulkan created to help port DX12 code over to Vulkan natively, you could in theory use the RT libraries already. Though I can guarantee it'd be more complicated without the official support to build more off of the ported code.
I don't doubt they are collaborating on a RT library. It's a complicated feature and reducing the effort for developers is key for them using it anyway. Leads to better implementations, shorter development time, and less money spent. Win-Win-Win for everyone. Though again I am definitely glad you are hearing of a collaboration. I would be thrilled for that!