If you book a garantee, they will give you that category or upgrade you. Depends on how full the ship is. Note: Booking a specific cabin is going to cost an average of $50 more p/p. However, you get the exact cabin you want. I have been upgraded 3 times on my 15 cruises. Twice I was NOT thrilled with the cabin. Once it was under the show lounge floor, another time from an inside to an outside, but the outside was very aft in the ship so there was lots of noise and vibration.
However, this did not deter me. We are booked in a balcony garantee for our next sailing in May. Good luck on your upgrade, I hope you get one and you are happy with it.