Get Comment With Meta value

WP_Comment_Query doesn’t pull comment meta. You can search by comment meta but the query doesn’t return that data. You could easily check this yourself by looking at the Codex.

You need to loop over the results and run get_comment_meta(), or essentially do the same via a filter on the_comments.

It is also possible to add to the data returned by filtering the “fields” clauses:

function add_cmeta_wpse_212423($clauses){
  //   var_dump($clauses);
  global $wpdb;
  $meta = "(SELECT meta_value
  FROM {$wpdb->commentmeta} 
  WHERE (
    comment_id = comment_ID
    AND meta_key = 'test_comment_meta')
  ) as test_comment_meta";
  $clauses['fields'] .=  ', '.$meta;
  return $clauses;
}
add_filter('comments_clauses','add_cmeta_wpse_212423');

I created a subquery. You could create a JOIN as well.