I suspect confusion with the WebAssembly Component Model — whose development is somewhat intertwined with that of WASI's.
It defines a function call ABI between sandboxes.
No object is in shared memory: parameters are passed by value or by handle.
Has its own IDL and ABI that languages' ABIs need to have adaptors to, if they don't conform.
How could WASI solve (or be involved in solving) this problem?
I suspect confusion with the WebAssembly Component Model — whose development is somewhat intertwined with that of WASI's.
It defines a function call ABI between sandboxes. No object is in shared memory: parameters are passed by value or by handle. Has its own IDL and ABI that languages' ABIs need to have adaptors to, if they don't conform.