Here's a part of an email from my TA.
"You are a category C-2 Guarantee and are booked cruise only. A guarantee means that at this time there is not a stateroom assignment available, however, you are guaranteed a stateroom in the category you have paid for or better. Your stateroom can be assigned up until the day of embarkation. "
As I mentioned I did get a 'real' assignment. My TA and O buddy both said that in all their years of working with O they'd never seen a problem with this. I said I still didn't like it. And eventually I did get a cabin.