I think that India bought that coal; China is now relying on Brazil, which is having its own problems.
Chinese sanctions on a broad range of Australian products were being supported by the Trump admin ("America First") but that is now changing. If conditions deteriorated and iron ore sanctions happened (by either China starting something in the South China Sea or some stupid Corona sanctions) then the Chinese economy would grind to a halt and metal prices globally would spike, and we'd be melting containers down for their scrap value.