So what's really in it for AA?
For AA management, nothing but the sack probably... therefore any future takeover by US is likely to be hostile (i.e. not supported by AA management).
For a hostile takeover of a company under ch11 protection to take place, the creditors would have to support it.
The bankruptcy court has appointed a board to represent the interests of the unsecured creditors.
Union members have seats on this board.
US will need to gain the acceptance of the majority votes on this board to be able to file its takeover plans for consideration by the court, by this route.
Thus - the unsecured creditors need to see
more light at the end of the tunnel from a US take over, rather than the current AA management rescue plan. (So, this announcement by US and the Pilot, FA & Mechanics' unions is important, because it is their way of saying "yes" to that proposition.)
Us bigger necessarily better?
For US management, presumably they do see bigger as better.
For AA unions, it could double as a negotiating tactic to pressure for improved membership outcomes from the AA management plan.