I would think that they have a pretty good idea now since the card has been out for about 18 months - certainly they'd have a good idea by year end.

Regarding the statement that the card seems weak, it's partially because they "listened" to us before the credit card came out that our big concern was dilution of status (hence having the credit card doesn't give any credit towards Diamond status - just automatic Platinum status which doesn't really give that much in terms of perks). And if they gave more bonus points (2x per $ spent) for more categories, there would be that much more points chasing award nights.