Booked on a TPAC 77W, chose 1A at booking (two months out). At T-24 hours, I got a text message that my seat has been changed to 1D "due to an aircraft swap."
Since this route uses 77W exclusively and there is only one version of J seating, I was doubtful. I called GS and they said, "We're very sorry, but the airport made the change and there's nothing we can do. It's either a broken seat or an air marshal." (Very surprised they'd say it could be a FAM!) As it turns out, 9A was still available so I swapped to that and I'm happy to have a bulkhead window. You can be sure I'll check out the owner of 1A...