Get bundle's default publication status
The default value is stored in the field's config, rather than the node type's. Currently it's not possible to get that value without having a node to work with.

This is alluded to in NodeTypeForm::form() (and also the save() method of the same class):

if ($this-&gt;operation == 'add') {
  $form['#title'] = $this-&gt;t('Add content type');
  $fields = $this-&gt;entityManager-&gt;getBaseFieldDefinitions('node');
  // Create a node with a fake bundle using the type's UUID so that we can
  // get the default values for workflow settings.
  // @todo Make it possible to get default values without an entity.
  //   https://www.drupal.org/node/2318187
  $node = $this-&gt;entityManager-&gt;getStorage('node')-&gt;create(['type' =&gt; $type-&gt;uuid()]);
}
else {
  $form['#title'] = $this-&gt;t('Edit %label content type', ['%label' =&gt; $type-&gt;label()]);
  $fields = $this-&gt;entityManager-&gt;getFieldDefinitions('node', $type-&gt;id());
  // Create a node to get the current values for workflow settings fields.
  $node = $this-&gt;entityManager-&gt;getStorage('node')-&gt;create(['type' =&gt; $type-&gt;id()]);
}


It goes on to set the options arrays for the checkboxes using that node:

$workflow_options = [
  'status' =&gt; $node-&gt;status-&gt;value,
  'promote' =&gt; $node-&gt;promote-&gt;value,
  'sticky' =&gt; $node-&gt;sticky-&gt;value,
  'revision' =&gt; $type-&gt;isNewRevision(),
];


So, for now at least, you'll probably need to do the same thing.