In other words, during the month of October all the regions of Japan other than Izumo are emptied of their gods, because all the gods in the entire land assemble at Izumo Taisha Shrine to discuss the year's events.
すなわち、出雲大社に全国の神(神道)が集まって一年の事を話し合うため、出雲以外には神がいなくなる、というものである。