I think its because Hasbro usually takes a while to send their shipments to Dorkside. I remember when I ordered the Wave 2 Captain America figures from Dorkside and it was the same situation as you have now. No complaints from me though as their customer service was very helpful and when the figures did ship out, it came almost instantaneously.
We actually got a small amount of them last week and processed some of the earliest orders. The bulk of our order is suppose to arrive any day now. Honestly it's really random, we've been some of the first to get stuff in the past but as you allude we got royally f'ked with the captn america wave 2. Unless u have really deep pockets and are prepared to pay for your own transportation costs from overseas (amazon & TRU) (EE & BBTS) to a lesser degree then you're at Hasbo's mercy and they will send them to you when they want to. thanks again for your business.