If it's getting out and getting to customers, then it's not a failed release.
Not ideal, but certainly not failed. This kind of stuff happens with simultaneous releases. Home countries (china in this case) typically get priority. Those on the other side of the world suffer lag. Only a few companies can pull off simultaneous global release of a consumer electronics product and get it close to right.
Also... never go by message boards as an indicator of success. People overwhelmingly ***** and complain online, while satisfied customers, remain silent and satisfied--they just don't rush to the internet believing that crying like a baby about their phantom being 3 days late will fix anything. It is no litmus for what the market is really doing. Quite the opposite.
I actually find it quite humorous how some people lack the patience to wait an additional three days. They get pissed off and frustrated because their item, that they are currently living fine without, isn't showing up on a day it was never promised to begin with. Canceling orders and placing new ones, blaming vendors, blaming apple (like this is apple's product), and making fools of themselves because they can't have their toy the day it ships form the wharehouse in Shenzhen. Important to keep in mind the only official release date from DJI's mouth to the press was "Early May."
Relax, wait. Your Phantoms will arrive before "Early May" ends and you will be able to fly it around for whatever time critical must-have-right-now-or-universe-will-end event you need it for. Complaining constantly and hassling vendors at their busiest time of year isn't helping.