How do I change the label and help text of the publishing status checkbox?
You can use hook_form_alter() to change label and help text
Use devel module to debug the label and help text change accordingly.

/**
 * Implements hook_form_alter().
 */

  function hook_form_alter(array &amp;$form, FormStateInterface $form_state, $form_id) { 
  if($form_id == 'node_page_form'){
   kint($form);
   kint($form['status']['widget']['value']['#title']);
   $form['status']['widget']['value']['#title'] = t('Published status label changed');
  }
}


After applying above code for basic page node form i was able to see the change in label of published text to Published status label changed