The 13 aircraft parked in dwc are passenger aircraft NOT freighters.
Earlier post:
13 777s parked in dwc
From the EK side :
13 777s are parked in DWC on a 3 month cycle.
At the end of each aircraft's individual stay it is returned to service and replaced with a fresh aircraft for its 3 month stay.
The 13 count reduced to 11 over the Christmas travel season which I read as saying that these aircraft will not be needed soon if ever again.