If the OP is concerned about traveling together in a premium cabin on the planned date, confirmed may not mean much if downgrades occur. Yes there will be a refund of the fare difference, but that doesn't help if one does not want to fly coach. Confirmed is different from having a valid seat assignment, but IMO it's worth the effort to try to move the rest of the family into business class seats that will exist on the aircraft.

OP should become very familiar with AA policy regarding downgrades, especially the priority ordering. Unlike IDB policies, this might be unpublished and also different from IDB priority rules. On most carriers, having paid a premium cabin fare rather than upgrading somehow should help, but having no status is bad in such cases. Checking in ASAP might or might not matter. In any event, get to the airport and the gate early. Try to board as early as possible too, just in case there are duplicate seat assignments and the GA decides to resolve the issue in favor of the first occupant.