Qin Mu sent the memorial asking to leave the celestial heavens to travel to the Jade Capital's Numinous Sky Hall. Soon, Celestial Emperor approved it and gave him a Heavenly Dragon Treasure Carriage as a show of his authority as a Celestial Venerable.
Qin Mu knew the approval came from the ten Celestial Venerables, not Celestial Emperor.
There were grudges between them, and they were busy trying to suppress one another. It was to the point that they didn't even have time for the Great Void or Carefree Village. Qin Mu's stay in the celestial heavens wasn't useful to them, so they let him out with some surveillance.
Yun Chuxiu tagged along too.