Well, I got a note from Skywards about concourse 3 opening in January.

Dear Mr. ........,

In January, Dubai will unveil another world first. And this one is particularly close to our hearts.

Emirates Terminal 3 at Dubai International Airport is being expanded to include a brand new, dedicated A380 facility. The only one of its kind in the world. Every gate is designed and built exclusively to accommodate the world's largest airliner.

The new home of our Emirates A380 fleet also features:
• Extra spacious, state-of-the-art Lounges
• Direct boarding from First Class and Business Class lounges to the A380's upper deck
...
..
It promises to transform your travel experience when you fly on the Emirates A380. In the coming weeks, we will be letting you know more about it and all the ways in which it will benefit you, so keep an eye out for further updates.

With the new concourse opening and the lounge infrastructure getting in place, I would guess that the time is ripe to announce the fourth tier.

But again, with EK, you never know...