Clearly, they are not compliant with WASI specifications built by the ByteCode Alliance, creators of WebAssembly. They are making their own web-assembly-thing not compliant with anything.
You forked the WASI Preview 1 and are making your own standards from it, and instead of working with the Bytecode Alliance, you are forcing your own standards.
As a matter of fact we pass more tests than any runtime created by the BA as reflected here:
https://wasi.fyi/