Sounding like M's defence lawyer here....
You have to consider here that the 5200's are still new and with all new product launches, you never quite know what demand will actually be once you have finished priming the dealers shop demo needs.
FWIW I ordered my last item on a Wednesday and received on the Friday same week. So, apart from the obvious differences in model and relative time from launch, you can't really make generalised sweeping statements like "Buyers beware ......."
If you hit the Xmas shutdown at the wrong time, that can be frustrating but such is life...xmas does that every year. Just be greatful M are French....they be out for the whole of August too ;-)
Don't let it spoil the enjoyment of your new toys.
Cheers
Nick