That seems to be correct. The phone agent did talk to her supervisor but they said that upgrades are flight specific. Today's SEA-BOI was F7 when I was rebooked but U0. U opened this morning and I was able to again pay my $29 to get into it. Good thing too as the flight filled up with standbys so I'm glad to have spent $29 to be more comfortable and have a few cocktails.

Glad it worked out! The lack of protection on rebooking is another one of those AS points that is easier to overlook when they offered better service and benefits than the big 3. As they move towards that same service level, those sort of things become more of an irritant.

Too bad you couldn't sprint from the remote gate to gate C10 and then board. That risks arrest.

Sorry about your ordeal, OP.

The GAs had likely already closed your flight in the computer and were unwilling to re-open it. It's unfortunate that they seem to be disincentivized to help connecting pax make even the last flight of the night, and even when that flight is running early.

For the record, the website seems to indicate that the "official" policy is that you need to be at the gate with a valid BP at D-30

Nevertheless, hopefully AS Customer Relations will issue you some comp. Please keep us posted on their response

Your seat was probably filled by another displaced passenger from a mess earlier, and even if they opened the door, the seat was gone. That's my guess.

A "few" cocktails on a ~90 min. flt? Be happy if you get > 1. I would have bought u a drink in BOI but we're fishing in AK. :)
Next time in BOI let me know.

Many unfortunate observations here:

I assume this was Friday?
Blue Angels were practicing in the early afternoon...How that impacted your 8:35pm landing flight, I am not sure.
They were flying over my house and when they were I took a look at the ATC flow via FlightAware. Flights were taking off to the north and had to make a curve around the the city to the west. Inbound were not affected much on the pattern running them down over Lake Sammamish. I didn't see this impacting capacity really. Also much earlier in the day.
I am not sure when there would have been low ceilings, maybe in the early morning but the rest of the day was quite clear.
I do know that the low ceilings in the AM excuse has been used for evening flights and possibly because capacity is so constrained that ANY delays any time during the day will compund into the evening.

As others observed, at this point, you can't really rely upon being able to connect in SEA anymore. These delays are also highly variable. They can easily be 90-120 minutes.
Seatac is rapidly expanding the number of gates and flights without anymore runways so this will continue until a complete meltdown in 2021 once some of these expansions are complete.

Blue Angels were indeed practicing, I had a Q400 flight that took off on Thursday at around 3 PM and we had a dramatically altered climb out to avoid their airspace after an insanely long taxi out.

All true but lets keep things in perspective. I have sat on the taxiway at ATL in a line of planes that went on forever for three hours and I have endured endless multi-hour T-storm delays at EWR. When I think about that the bus gates at SEA don't compare.

I'm freaking out
 

ok, you guys have me freaking out. In 2 weeks, I fly JFK - SEA (AS 349) with 1 hour layover then SEA - ANC (AS 57). I had a longer layover and AS changed the flight schedules a few months ago. Any way for me to know which gates I will arrive and depart from? This trip has been in the works for a year. If I miss the second leg, friends who are meeting me in ANC will be stuck without a car, hotel, etc.
Thanks.

Ouija board? Tarot cards?

You're asking for gate assignments two weeks in advance. That's not going to happen. If it does, make sure you get some winning lottery ticket numbers.

SEA-ANC isn't like SEA-BOI, there are regular flights to ANC available at all hours, if you miss your flight you will be rolled to the next one.

There is really no way to know what gate you are scheduled into until a few hours prior to the flight, and even then it can change up to the time you arrive.Since you are scheduled to arrive at noon that is a slower time at SEA so gates should not be an issue. I don't think the transcons ever use the bus gate so assuming you are not delayed in NYC you should be ok, but not by much.