The .torrent file can list multiple trackers. If it includes TPB's old trackers, connections will fail but the DHT and other trackers usually manage just fine. In fact, TPB said that trackers are obsolete ("not up-to-date") and that everyone should just use DHT and peer exchange (PEX) instead of relying on centralized trackers from now on. Some people still use trackers, but it's not really necessary.