I wonder how much capacity is sold immediately after the launch of next summer's programmes, especially when the launch is before the end of the previous summer season. I imagine it's in the main capacity sold to families looking for cheap deals, and for whom price is more important than timings, service and the like.
Personally, I'm hard pressed to forecast, with any certainty, what my circumstances will be 6 months from now, let alone more than a year. It appears to me more like a cash-flow building exercise, getting fares, or deposits in from customers as early as possible, to spend over the leaner winter period.