I think not specifying the shader language / byte-code makes at least sense for those native WebGPU implementation libraries (of course not for the WebGPU standard itself).
For instance, currently Dawn comes with a lot of code to translate and validate SPIRV to the underlying shader languages or byte-codes. When using Dawn as a native library to get a friendlier cross-platform API over Metal, Vulkan and D3D12, it might make sense to do the shader translation offline, and feed Dawn directly with Metal and D3D12 shader bytecode. The strict validation isn't really needed in such a use case, the shader translation doesn't need to happen at run time, and the executable can be a lot slimmer.
Ideally I'd like to see both in web backend, SPIRV as base, but also have a quasi-standard textual language (might be WHLSL, I don't care, but just don't offer WHLSL as the only way to get shaders into WebGPU).
Both D3D12 and Metal allow to either feed shader bytecode to the API, or translate from shader source during run time.
For instance, currently Dawn comes with a lot of code to translate and validate SPIRV to the underlying shader languages or byte-codes. When using Dawn as a native library to get a friendlier cross-platform API over Metal, Vulkan and D3D12, it might make sense to do the shader translation offline, and feed Dawn directly with Metal and D3D12 shader bytecode. The strict validation isn't really needed in such a use case, the shader translation doesn't need to happen at run time, and the executable can be a lot slimmer.
Ideally I'd like to see both in web backend, SPIRV as base, but also have a quasi-standard textual language (might be WHLSL, I don't care, but just don't offer WHLSL as the only way to get shaders into WebGPU).
Both D3D12 and Metal allow to either feed shader bytecode to the API, or translate from shader source during run time.