"with only 5 A380 with Crew Rest Compartment ?"
Now EK has six A380 with Crew Rest Compartment!
Besides A6-EDA/EDB/EDC/EDD/EDE; the A6-EDM also has a Crew Rest Compartment!
Although at the moment 5 are enough to fly daily to JFK and SYD and 3 weekly flights to YTO.