Commenter meant straw buyers as in buyers of Chinese rare earths that do so at the behest of the US DoD while under the guise of buying the metals for their own use internal to whatever country they are based in.
China wants to move up the value chain. They don't want to continue to be the colony supplying raw materials (or even slightly refined materials) to the "first world". China wants to be building those electric motors - which is where the value & profits are located.