First, let me apologize for the size of this photo. I've tried every trick I know but Photobucket won't let me post a reduced version. I've spent about an hour trying, and I must move on. Anyway . . .
I thought this might help. I took this picture in June 2006 when guests were still staying in the North Wing. We had already heard about the new tower and changes to the Concourse on a previous trip and had expected to see lots of construction on this visit, but the construction at the north end of the Concourse was all that was happening at the time. CM's were saying it was only minor refurbishment, but DH said it appeared to be structural work in preparation for the walkway connector. I took the photo in the evening after the workers had left for the day, but while they were there all the work was being done on the outside. Concrete platforms were lifted, rebar was visible -- it seemed like more than just a window washing. If I had to GUESS, I would think this is where the walkway will connect to the main tower. As deej696 pointed out, everyone coming from the new tower wouldn't necessarily be headed for the monorail so it wouldn't be prudent to route them there where they'd add to the congestion on the monorail platform.
Again, I apologize for the size of the photo. I have a couple of others taken from the Concourse level, but they don't shed any more light and, because of the size, I won't bother posting them.