Since Generations isn't Hasbro's main line or focus, they (Hasbro) have been very unreliable in the past with the waves... some had push-backs of a couple months (based on the changing estimated release dates on BBTS). So it is unfortunate that the "middlemen" have to deal with excited and/or agitated customers.
(Remember how long it took them to get in Springer and Blitzwing, or at least a decent supply, as I think Hasbro only sent them a fraction at first and took a couple months to get in more to send to BBTS.)