Is there a way to alter output/markup for a field in node edit view?
You can use hook_form_alter or hook_form_FORM_ID_alter

You'll need the ID to target specific forms; otherwise, you will endup altering every single form. See How can I find the form ID of a form?

Example of hook_form_FORM_ID_alter:

function mymodule_form_node_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  /* @var Drupal\Core\Entity\FieldableEntityInterface $node */
  $node = $form_state-&gt;getFormObject()-&gt;getEntity();

  if ($node-&gt;getType() == 'article') {
    // Alter the 'article' form here.
  }
}