Yeah, that's a big if. In theory there's nothing preventing good compilation to Vulkan compute shaders, in practice people just aren't doing it, as CUDA actually works today.

I also agree that Vulkan is more promising than OpenCL. With recent extensions, it has real pointers (buffer device address), cooperative matrix multiplication (also known as tensor cores or WMMA), scalar types other than 32 bits, proper barrier (including device-scoped, needed for single pass scan), and other important features.