Not really weird. Palo brunch especially is a highly sought after meal. With it only being offered two days on this cruise means that the available slots go really fast. Keep in mind that Concierge and
Castaway Club Platinum members get first shot at 120 days out followed by CC Gold at 105 days out.
The good news is that there are usually some time slots available for booking once you get on board. Check the Navigator that they will hand you when you check in at the terminal. It will give the time and location to go to to try for a brunch reservation.