but do they still have the midnight buffet?
Royal Caribbean has gotten away from doing midnight buffets every night. This is because is was usually a lot of wasted food and they simply became less popular. Plus, on the Voyager and Freedom classes there is food available 24/7 in the Cafe Promenade.
On the typical 7 night Caribbean cruise they will now have "Midnight Delights" on most nights. These are snacks served in a couple bars and the casino. They'll usually have one midnight pool party with a buffet line (Mexican and Caribbean-style food is common). And on the Liberty Of The Seas last year they did have a "Culinary Extravaganza" buffet on one night. This was in the Windjammer.