I would bet money that Z is right — it’s most likely a synthetic delay added to compensate for the now-absent HD Radio stream (8.2 seconds for Hybrid AM HD, if I remember right?). That was so when the HD signal was lost, there was no timeshift when a receiver dropped back to analog AM. If WEFM is only 5 or so seconds ahead, they might have their own delay of a couple seconds with relayed audio from the mother ship.