Meta tags form fields are missing when adding a new taxonomy term

The Meta tags field set is present when editing an existing taxonomy term, but not when adding new terms.

  $bool = (isset($form['tid']['#value']) &&
    !isset($form_state['confirm_delete']) &&
    !isset($form_state['confirm_parents'])
  );

By removing the test for tid being set...

$bool = (
    !isset($form_state['confirm_delete']) &&
    !isset($form_state['confirm_parents'])
  );

the form elements show on the term add form, and the meta content gets saved correctly in the db.