No way they are even thinking about schedules 80 days out. They can't even tell me for a cruise 9 days out if they are doing Halloween and which night it is.
Instead of asking which night is Pirate, ask them if the dining rotations are requestable yet. Whichever night is your restaurant duplicate, that will be you "pirate" menu (or non-rotation menu if they don't do pirate.)
For example, if the rotations are AERR, ERAA, or RAEE then the last night is your best bet for Palo night. If they are AEER, ERRA, RAAE, then the 3rd night is the best bet.
Edit: I realized not everyone might know what those codes mean. R=Royal Court, A=Animators, and E=Enchanted Garden (Those are on the Dream, Magic will have different letters) . On cruises over 3 days, you will duplicate one or more restaurants. So if you find out what the 3 rotation options are for the restaurants, you at least know which nights are a duplicate in the same restaurant to give you a better shot at guessing which night you want to skip it. Also, if your cruise is 5+ days, chances are the Pirate is NOT the last night. So if your rotations are say AERAE, then the 4th night is the one to skip. If it's AEERA, then the 3rd night is the one to skip.