you make it sound as if Apple only sends out shipments once pallets are full. As another user mentioned earlier, EU in some case could be easier than the US to import as they don't need to deal with separate state regulations as everything is managed by the single market rules. Plus, Apple has been shipping to the EU for ages, the OP of the quote seems to be from Aus and I can't speak for Aus but I imagine it's pretty much the same story.
Logistics company will try to fulfil the orders anyhow they can to meet the demands of the clients, the only way it would be a logistics issue is if the deliveries were delayed after orders went to P4S or Shipped. At this point they are still being processed which implies the ball is still on Apple's court.
To further drill on regulatory matters, it's not like the FCC where you need to get all devices pre-tested, for imports all you would have to do is meet import regulations which Apple has been doing for years, so I can't imagine a laptop with a new touchbar would make that much of a difference.
The whole point of the pre-order process is to put orders in a prioritised line where the principle of first-come-first-served applies. RE: critical mass, since when do we need to hit a critical mass to add couple of new laptops on pallets that are going to other regions anyways?!
The whole point is, Apple is unfairly favouring the US without a proper explanation to the rest of the world as to why it's doing so. It's like going to a restaurant, you were waiting at one till to be seated and you're waiting for an hour, I decide to come later, line up behind a longer line for a different server, and the restaurant decides to only seat people from my line. Yes you will get your food at some point but how would you feel if someone that came after you got served first?