There are no aircraft that fly TATL with AA or BA that *don't* have business class.

What happened there?

Had you been downgraded to Main Cabin because the J cabin was smaller on the new aircraft? Was the flight not actually subject to an aircraft change, but in fact overbooked?

EDIT: A quick search shows AA729 as operating with an A330 as booked today, though it is a -200 variety.