Honestly pick between Vulkan and DX12 is very superficial.
But you can easily make Vulkan run on macOS. Not sure what would be the reason to use DX12 in the new project today given free choice of technology, especially when team comes from OpenGL.
but why would you pick the worst API?
The reason you use DX12 in a new project is so that you can get good linux support.
I'm making a joke, but it's also true.