The rooms covered with the scaffolding are not in service. You don't need to worry about being assigned to one.
The rehab of the area surrounding the quiet pool and Community Hall building is finished. If you request a room there, you should not be able to see any scaffolding from your balcony. These rooms are not close to the elevators, but they are closer to MGM (walking path) than most of the other rooms.
The outside rehab of the rooms overlooking the hotel entrance and driveway has n't started yet. Some of these rooms (on the higher floors and near to the tennis courts) have views of the Illuminations fireworks from the blaconies. These rooms are also farther from the elevators.
Most consider the rooms with a view of the Boardwalk to be the best. To the best of my knowledge, the rehab of these is also finished. However, there is still some work going on around the shops on the first level.
It sounds like a lot, but really, none of the rehab work will interfere with your vacation. Just kick back and enjoy!