If i read this correctly , it sounds like you took a BE guarantee .
This means that you have a Balcony in a BE category or higher and the cabin assignment will be assigned to you at a later date .
Depending on the date you are traveling , i have seen the cabin be assigned as early as 6months ( sometimes earlier ) prior to the Cruise date.
I have never been sorry about the Guarantee ,because i have always at least gotten a 2 category upgrade .
For the price a guarantee is a great bargain, it is not for everyone. Especially if you are someone who cares where on the ship you are.
I hope you get a Great Upgrade and enjoy your Cruise...