I seriously doubt that
DCL is going to cancel those December cruises. Remember the Wonder has been in LA almost a year, and LOTS of folks rebook while onboard. I myself rebooked for the week before Christmas, and got a great deal on the SPH room + onboard booking discount. I don't think there are any SPH rooms left on my cruise. And all but one of the suites are already sold. Over a year out. So I think it's possible the sales for the Christmas cruise are good. I know I had wanted to try the Fantasy, but it's just too much- so we are sticking with the Wonder. I bet other folks are too.
Its taking time to establish a permanent client base on the West Coast. I know so many people who have taken/have booked their very first DCL cruise on the MR! But for whatever reason DCL has done little to no radio/tv advertising that they even have a ship out here. Thats in stark contrast to the ads they did when the Magic was here in the summers past. It's almost a word of mouth thing. Very strange on DCL's part.
I do think some people will move those bookings perhaps if the 2013 Wonder itineraries are interesting. So while some might be dummy dates, I don't know why folks would pick an already expensive week for their dummy booking.