Удаляем slug автора или меняем на наш

add_filter('author_rewrite_rules', 'no_author_base_rewrite_rules');
   function no_author_base_rewrite_rules($author_rewrite) { 
      global $wpdb;
      $author_rewrite = array();
      $authors = $wpdb->get_results("SELECT user_nicename AS nicename from $wpdb->users");    
      foreach($authors as $author) {
         $author_rewrite["({$author->nicename})/page/?([0-9]+)/?$"] = 'index.php?author_name=$matches[1]&paged=$matches[2]';
         $author_rewrite["({$author->nicename})/?$"] = 'index.php?author_name=$matches[1]';
      }   
      return $author_rewrite;
   }
   add_filter('author_link', 'no_author_base', 1000, 2);
   function no_author_base($link, $author_id) {
      $link_base = trailingslashit(get_option('home'));
      $link = preg_replace("|^{$link_base}author/|", '', $link);
      return $link_base . $link;
   }