I'm afraid the answer to your question is: "No you're not missing a setting." CiviCRM will send out emails for bulk 'registration status' updates automatically with no way to stop it.
For some projects - we'll use a simple Drupal buildForm hook
for other backend registrations/updates (below) - but this does not help with the bulk actions.
function mydrupalmodule_civicrm_buildForm( $formName, &$form ) {
if ( $formName == 'CRM_Event_Form_Participant' ) {
// please no - really - yes - no confirmation emails...
$form->assign('email', '');
$form->assign('batchEmail', '');
}
}