Question... when they give you your Wave date then you have 48 hours notice. Do they provide a map with the seats available for you to upgrade to?
I don't know about the Wave approach specifically but when we were given new seats to accept or decline for relocation they provided us with a map and a seat-view image. The image was, for us, an approximation and the tiniest bit misleading, but when you looked at the map in conjunction it gave a very good idea of what we were getting. I expect they don't have 15,000 seat images, so the approximation was fine IMO.