First, per AA:
Boarding times:
"
30 minutes prior to departure From/To the United States and:
Europe
Middle East
Asia
South American destinations: Asuncion, PY; Brasilia, BR; Belo Horizonte, BR; Curitiba, Br; Buenos Aires, AR; Rio de Janeiro, BR; Sao Paulo, BR; Lima, PE; Montevideo, UY; Porto Alegre, BR; Recife, BR; Salvador, BR; Santiago, CL; Sao Paulo Viracop, BR"
http://www.flyertalk.com/forum/ameri...ar-2017-a.html
We've had many posts regarding:
Boarding times - for many international flights, they begin boarding 45 (or earlier - see above) minutes prior to scheduled departure
D-0 - wherein many gate agents begin boarding early
Losing upgrades because one was not in the gate area before they began boarding, which is when they process upgrades
Whether it's AA policy or not seems immaterial, because the evidence supports gate agents are empowered to do pretty much anything they want as long as the jetway is closed and the aircraft is ready for pushback on time.
These posts have been full of angst - why should Club members be denied Club access merely because the gate agents might choose to process upgrades by voice calls, leaving those not present out of luck and upgradeless? Because D-0 is their priority. Apparently AA
will penalize them for a late departure if it's due to gate checking bags because there were too many passengers with bin bags, or other reasons presumably under their control, and AA appears not to penalize them for early boarding calls and using upgrade in order but by voice call.