We were there in early December when the Moana area began CM previews and it has no affect on getting around the park. It is actually a small percentage of the total construction being done.
From what I saw from the monorail there is still a lot of work to be done. As in the biggest structures behind the wall were still metal framing and that's it. Hopefully the walls come down by the end of the year but I doubt that the new attractions will be open. There's just too much work to do.