How can I know if a type of content is moderated?
You should be able to get that from ModerationInformation:: shouldModerateEntitiesOfBundle(), via the content_moderation.moderation_information service:

$moderation_info = \Drupal::service('content_moderation.moderation_information');
$entity_type = \Drupal::entityTypeManager()-&gt;getDefinition('node');
if ($moderation_info-&gt;shouldModerateEntitiesOfBundle($entity_type, $content_type-&gt;id())) {
  // ...
}