My experiences with the Dr. Seuss breakfast reservations. Same ship on different sailings.
1. Could not make reservations for months. I checked daily. Then a couple of weeks before the cruise, bookings became available and I made our reservations.
2. For cruise in March next year, bookings were available soon after booking and we have our reservations.
3. A relative told me that she was able to make reservations on Embarkation Day. She said there was a table set up on that day for reservations.
Good luck.