_tracker_remove does not properly update tracker_user and has a redundant db_update for tracker_node

      // And then we push the out the new changed timestamp to our denormalized
      // tables.
      db_update('tracker_node')
        ->fields(array(
          'changed' => $changed,
          'published' => $node->status,
        ))
        ->condition('nid', $nid)
        ->execute();
      db_update('tracker_node')
        ->fields(array(
          'changed' => $changed,
          'published' => $node->status,
        ))
        ->condition('nid', $nid)
        ->execute();
    }
  }

There appears to be a redundant db_update in _tracker_remove. The second one supposed to apply to tracker_user if the module follows the same structure at the D6 verison. If this is not the case the second db_update probably should be eliminated as unnecessary. This should also be backported to D7.

I have no way of testing this on D8 (not yet familliar enough with D8).