Isn't the A380 only going to be around 70 - 80 passengers more than the 777 - so say 150 extra on a typical turnaround.
Wasn't MAN at it's peak handling about 5m passengers a year more than it does now - say 13,500 a day on average.
So your concern is that airport that has at least 13,500 passengers per day capacity (much more in reality because of improvemnts and the fact it wasn't maxed out even at 22m+) won't be able to cope with an extra 150.
I'll go out on a limb here and say all will be fine.