the drink service is only offered mostly on lunch service on flights departing between 7Am and 7pm lasting more then 4 hours 30 minutes .
As you like service is only on flights 12 hours or more , sometimes 10 to 12 hours , offered as one of two services ( rare routes ). This service was modified since January , chocolates and fruits offered from the galley , but now full bar service offered ( instead of water and orange juice ) along side a vegetarian pizza (Ex DXB), cheeze sandwich (ex USA), hot beef or veg pie ( ex Australia ).
On the long sectors i.e. SYD MEL USA , meal carts are followed by a bar cart ... Main reason would be to allow crew to go on rest to be legal to work a 12 + hour flight. Mainly on the A380, as the 777 holds less passengers , the drink service before meal is mostly offered on the ultra long flights and allows the service to be finished and sufficient break to be taken by the crew.