Perhaps a few exceptions in the past generation of guys at Legacy Carriers but USUALLY, it is usually wisest to take the earliest route to upgrade available, because;
1- once you get upgrade, your life changes dramatically for the better, on and off the job
2- you are more marketable should you choose to leave
There are a few things about EK, that make a move as an F/O onto the A380, not the best option. (excluding present rosters and lifestyle)
1- EK doesn't give a darn about seniority
2- EK will alter the rules when cost savings are achieved (ie. 2 years frozen on the A380 could feasibly increase)
3- An experienced F/O on the A380 is a valuable commodity,especially when 'new-to-Airbus' Captains become eligible for it
4- Just because your seniority dictates that you should be the next pilot eligible for Command Upgrade, does not mean that EK will let you slide back to the A332 on schedule.
5- It would cost EK money to allow current and experienced A380 F/O's to upgrade on another type. First, there would be a 6 month RH seat period on the other type. Second, they would have to train another F/O to replace you on the A380 and this would all have to take place in those 6 months plus the 2-3 training months you need for upgrade.
6- Upgrades will not occur from LH seat A380 to RH seat A380
Take the shortest possible route to upgrade is my advice and the A380 will likely result in the longest upgrade timeframe.