You'll have to export DXVK_FAKE_DX10_SUPPORT=1 for WoW to work. From reading your log it should be enough.
Maybe add to quirks?
Added an entry about DXVK_FAKE_DX10_SUPPORT to https://github.com/doitsujin/dxvk/wiki/Common-issues, this should suffice for now.
DXVK_FAKE_DX10_SUPPORTx1 2018-07DXVK_FAKE_DX10_SUPPORT=1x1 2018-07
Software information
World of Warcraft
System information
I ran with VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/radeon_icd.x86_64.json as I thought I might have been having issues with using a PRIME system
Log files
Wow-64_dxgi.log