Inventory in business T-T has been easier, until now, to access than in economy.
Sounds like possibly a similar case in terms of AA booking on QF across the Tasman. But although QF only has 12 J seats in their 738s, it doesn't seem to affect any AA member booking a J award seat.. And surely NZ can't sell out J for every trans Tasman flight.. Because if they did, I'd see them bringing back J to the A320.