I can see that the 787-8 is a significant reduction in capacity from the A333, but as long as they keep it as one of the double dailies, and keep 14flights a week for the whole year instead of winter 14 and summer 10, there wouldn't be much of a year-round reduction in capacity.
But I have to admit, after they introduced double dailies last year, I expected them to increase capacity by stepping one of them up to a 77L, rather than decrease it or keep it the same. Unusual of a growing gulf airline.