Originally Posted by
controller1
My understanding is once the list appears on the app, the list is under airport control. I based my previous answer on the following from aa.com:
Step 2
If your upgrade is confirmed, we'll send an email to the address in your AAdvantage profile to let you know you've been upgraded.
If you're not upgraded right away, we'll keep checking for upgrade availability – up to 3.5 hours before your flight.
Not always the case. I've been auto-upgraded while in the T-4 timeframe before any gate agent started prepping the flight.