special case: if it’s an award ticket, you have to deal with AA for any changes inside T-24 (i.e., once AA has control of the PNR) … if you ultimately cancel the reservation, it’s likely to be a long and challenging process to get the miles reinstated

< above is the TLDR summary, details follow >

I arrived IAD on a TATL ~630pm to discover AA had automagically rebooked my sunrise flight (IAD-DFW-SEA in F to IAD-CLT-SEA in Y) due to a pre-emptive cancellation for a weather waiver; their phone wait time was over an hour

while on the mobile lounge to Customs & Immigration I booked a different AS F award on AA metal leaving from DCA at 2045, overnight ORD, and on to SEA at 0955 (the best part of this was NOT having to roll out of bed at an IAD-area hotel at 0400)

called AS from the Uber; CS phone rep cancelled the original trip, but two weeks later I have yet to see anything but “refund is in progress” emails from both AS and AA