add_action( 'post_updated', function( $post_ID, $post_after, $post_before ) use ( &$wpdb )
{
    if(
           'editing' === $post_after->post_status
        && ! in_array( $post_before->post_status, [ 'editing', 'publish' ]  )
        && 'post' === $post_after->post_type
    )
        $wpdb->update(
            $wpdb->posts,
            [ 'post_date_gmt' => '0000-00-00 00:00:00' ],
            [ 'ID' => $post_ID ]
        );

}, 10, 3 );