I had a similar reservation at BWV and despite making notes when the reservation was made, mentioning it check-in, and speaking to a supervisor later, we still had to pack our stuff and move, twice.
We started with a studio, expanded to a 2 BR when my parents showed up, then shrank to a 1 BR when they left. I had hoped that we could just basically move through the portions of a single lock-off unit (although I knew it was not guaranteed). Despite making all the arrangements I could and making all the polite requests to everyone I could, we had to pack, store our stuff, and check into a new unit later in the day both times.
I knew this was a possibility though so I really couldn't complain. But it sure was a pain to pack up all the clothes and supplies for a family with 1 and 2 year olds, then be homeless for several hours including nap times.
So be aware that you can hope you won't have to move, but it is NOT guaranteed, as I experienced. Just friendly words of warning.
(It was still a great trip and we loved BWV)