This is disappointing news, especially for someone who is just coming in to the tournament scene. I never expected to be able to receive something like this myself (especially being in Australia), but I really appreciate how much the ANRPC is doing for the game.
Off the top of my head, I would not be surprised if "logistical issues" were code for "technical issues." FFG is a subsidiary of WOTC, and their track record with any sort of technical stuff is hideous (See their websites, DND tools, MTGO). It would not phase me in the slightest if they did not have a method in place to secure earlier registration, or the ability to change details on tickets, without having to delve into the back end. Basically, they're not willing to offer a service to a small section of the community as that would set precedent for others, and because they have no easy means of completing the task, it would create substantial work for them.
I honestly hope this is the case, since that could mean that with some small tweaks, the system could be changed such that what ANRPC are trying to do is possible. Unfortunately, I wouldn't hold our collective breaths.