Let OP make the decision. He booked F and if he wants F he ought to do the research on F alternatives. If he is OK with J, he is fine and just needs to slug out the fare difference issue which will be a fight.

The key for OP is that he has to do the research rather than asking AA for alternatives. That simply doesn't work well.

There is a good chance that there will be further schedule changes, so keep checking online. The days when you could reliably expect a notification ended years ago, and that is more true for flights which are months away.