Recently, they have offered to move you to a different cabin if you’re positive, basing that on the day you show symptoms or test positive. Or, stay in the same cabin, but in your case, it would not be the same cabin.
Even, going back a year or so, they have given choices to guests who were on b2b’s if they wanted to disembark or stay OB. So, ultimately, it is up to the ship.
So, don’t think about that. Just think positive and enjoy your cruise.