Someone I know applied for this card just prior to the upgraded offer, which went live in August, IIRC. The previous offer was 10K miles on first purchase. The account was closed, within two or three weeks of being opened; however there were a few transactions and the AF posted (and the bill was fully paid) before the account was closed. Long story short, the statement did not show any miles awarded, but a few weeks later the 10K miles showed up at Asiana, which was a very pleasant surprise. So far the miles haven't been taken back. The AF was refunded, as well, though it took a few weeks.

This same person applied for the new version of the card (with the 25k/38K mile offer) as soon as the other card was closed, and has received the 25K signup bonus, as well. However the AF was paid on the second account.

I should add, none of this would have happened without the recalcitrance of B of A. They were approached at least half-a-dozen times by chat and by phone, and simply asked to upgrade the 10K offer to the newer, better offer. They consistently refused. And what was funny was that when the first card account was closed, B of A basically begged the cardholder not to close the account, seemingly oblivious to the fact that the cardholder had made it quite clear that closing and re-applying was absolutely the last resort. All they had to do was agree to upgrade the card to the new offer. So in the end, the cardholder basically got 35K miles (the initial, unexpected 10K plus the expected 25K from the second card) out of B of A for one $99 AF.

I'm sure that doesn't quite answer your question, but that was the experience of the person I know.