The Assistant Secretary may initiate a proceeding to review any antitrust immunity previously conferred by the Department's predecessor or the Department in any section 41309 transaction. The Assistant Secretary may terminate or modify such immunity if the Assistant Secretary finds after notice and hearing that the previously conferred immunity is not consistent with the provisions of section 41308. In any proceeding to review such immunity, the proponents of the immunity shall have the burden of justifying the continuation of previously conferred immunity under the provisions of section 41308.