בחר אוטומטית קטגוריית נושא על סמך קטגוריית הפוסט?

While there isn’t a dedicated tags filter, there is a general filter you can use: wpdc_publish_body. In your case it’ll look like this

add_filter(  'wpdc_publish_body', function( $body, $remote_post_type, $post_id ) {
   // code to get the post policy category
   if ( // if there is a post policy ) {
      $policy_tags = // map the post policy category to the appropriate tag(s)
      $body['tags'] = $policy_tags
   }
   return $body;
}, 10, 3);