They are adding the steakhouse and Italian restaurants, so maybe they think enough people will do those to not need the upper level of the one dining room? Plus w/ Guy's Burgers and Blue Iguana Cantina, maybe they're finding more people are eating there for dinner on the other ships with those options?
No disco is not a big deal to us...we never hit the disco anyways. I'll probably spend my evenings either in the piano bar or Alchemy, and DH likes casino and Punchliner.
Past Cruises -
Carnival - 20 cruises, 106 days (Platinum)
Royal Caribbean - 2 cruises, 10 days (Gold)
Norwegian - 2 cruises, 10 days (Bronze)
Disney - 2 cruises, 8 days (Silver)