Mayfly wrote:I expect they realised no-one was going to cough up for 558 this year....

I think you're probably right, although you'd have thought that they'd have benefited from as much publicity as possible by booking early and making it known. A large number have people will have already checked and seen that 558 wasn't on the list and probably won't hear about the last-minute booking.
I did also hear there were one or two other cancellations which may have eased the financial issue a little, though what those were I don't know.