Get Objects While Deleting term

Use the pre_delete_term hook, which fires before the actual deleting occurs, so the relationships will still be present.

function wpse_296972_pre_delete_term( $term_id, $taxonomy_name ) {
    if ( $taxonomy_name === 'organization' ) {
        $objects = get_objects_in_term( $term_id, $taxonomy );

        // Do something with $objects.
    }
}
add_action( 'pre_delete_term', 'wpse_296972_pre_delete_term' );