Yeah thats what I'd assume - some wording in his current contract to state that. Its too obvious a scenario for it to have been missed by lawyers, agents etc. No idea though, just guessing.
Re long, I have thought for a while that he is our best goalscoring option up front if we can get him interested and back to the form of pre covid... looks like he's out injured just now though according to the official site - return date TBC.