Do you use Award Wallet? I get about 3-4 gate change alerts to everyone that AS sends out.
The last time I flew into SEA, the gate changed 6 times in 45 minutes the night before departure from N to C to B and back to C. We actually ended up at N. I think SEA is just playing a "this might work" shuffle. When they think it is all set, they send out their own notification, realize it isn't going to work and start the whole process over again.
AW also notifies me about delays before AS does.
James