Is there really that much premium traffic? Premium corporate travel is down. Post #brexitvote London premium traffic expected to go down.
Dubai government is probably second biggest customer of EK premium cabins. With oil prices and cash crunch, that may be down. Even if it is not down, is it real revenue?
Reconfig is not cheap. Single F suite hardware costs $150k-250k, J seat costs $50K-100K. EK no longer has access to easy money and $6-$10 Million to redo entire interior is down the toilet.
Like Wizofoz said without cattle class and empty premium will bleed cash. At least on 3 class planes, you can offer free upgrades and make premium cabins look full, a
PR stunt.
So what ever airlines say, cattle class are important factor for route survival.