That's the sort of decisions being made: do I cancel and lose this money. I don't many could swallow the loss and still went.
My guess is it's a trip most book a year out (ie after returning from their last one) so the decline will be alot more noticeable around October
The article's main point is that bookings are down from the year before in the first 4 months of this year.
I'd imagine their reference point to bookings being "the worst they've seen" this summer is last summer.
i.e it was hot as hell last summer yet numbers were better than they are this year