They appear to blindly put up the dates they are given by the manufacturers. It is almost as if they get given the data and then enter it straight into their system for the shop.
I mean the fact that wave 5 was supposed to be out before wave 3 (and there being no mention of wave 4) should have been a warning sign that they were never going to be out in March.
That date being so far off I'd probably blame Hasbro for. If Hasbro said they'd have the assortment to them by March, and gave the go ahead for pre-orders, then what else are they going to do?