I called the GM's office at the YC several weeks ago. I asked about any rehab at the YC, specifically in concierge. I was told that, yes, the concierge area is going to be redone this year. At the time of my call they did not have the specific dates, but told me to call back when I had specific dates for our trip. We are staying at the GF, so I never called back. The concierge lounge is to be rehabbed and expanded, and the CM told me that the rooms are being done, too.
We were booked to stay at the GF in the main building in 2000 during the rehab there. We were able to book the reservation even though the guest rooms in the building were shut down. They used another building for GF concierge guests. If the YC concierge is redone, I would assume that they will set up concierge in another area of the resort temporarily or give you access to the BC.
One reason that we decided not to stay at the YC this year is that the CM in the GM's office was a little vague about work on Stormalong Bay. I know that the resort is being prepared for the grand opening of the new DVC at the BC which is scheduled for later this year. IMHO I would hate staying at the YC without Stormalong Bay.