I am not sure how you "lose" an arrival slot behind the A380. Wake separation is wake separation A380 or not. The same could be said for traffic following a heavy? The flow rate into an airport should take into account the number of heavies per hour?
Out of interest, with increased spacing on arrival is it not possible to get a departure out in between, even with the aircraft rolling to the end of the runway?
When the A380 started into YYZ they used full reverse on landing and made all the high speed exits. They were told that they didn't have to because they were causing a lot of "detritus" to get blown all over the runway and taxiways. They usually now roll to the end. Both tower and approach work around it.