I think instead what would be needed is a wgpu native runtime support for TVM. Like the implementations in tvm vulkan, then it will be naturally link to any runtime that provides webgpu.h

Then yah the llm_chat.js would be high-level logic that targets the tvm runtime, and can be implemented in any language that tvm runtime support(that includes, js, java, c++ rust etc).

Support webgpu native is an interesting direction. Feel free to open a thread in tvm discuss forum and perhaps there would be fun things to collaborate in OSS