Yep -- that's what happened. You can confirm by checking seatmaps on AA.com and asking to see only First Class seats.

The same thing happened to me on a recent LAX-ORD-LAX trip. Me, wife and toddler were all booked (together) on coach tickets in the biz seats. AA decided to sell those biz seats as "First Class," so without even notifying me they yanked our confirmed seats and scattered us in the back of the plane. Fine, whatever. Then they changed their mind and re-opened the biz seats to premium coach pax -- again without notifying me. The business cabin filled-up with different elites, leaving us scattered in the back even though we had booked months in advance. I guess the lesson is -- keep checking back to see if anything changes. Those seats might be sold as coach again before the flight takes off.

Good luck, and enjoy your trip!