Since posting, I’ve learned some extra context that may or may not be true but would be very relevant here. Supposedly, Sony are the ones in charge of the actual store page. Which would mean that it was their decision to have it listed in countries where you can’t make PSN accounts.
Meaning that there are two mistakes here: Sony knowingly listing it, and Arrowhead not making it clear that the optional account linking was temporary. The second of which the CEO of Arrowhead has already taken the blame for on Twitter.