It's happened quite often - it's called a "pop up" dinner. If there are any on your cruise you'll see them listed when you go online to book specialty dining. That, plus the Pinnacle will miraculously have NO available openings for that night - it'll be booked under a different dinner name. For my upcoming Zuiderdam cruise one night will be Morimoto popup, which will be held in the Pinnacle Grill.