Originally Posted by
channa
Another risk would be a misconnect. You're technically on a Y fare, so if your AUS-IAH is late, they'd rebook you in Y IAH-SEA, if F were not availabile.
And if you were on an F fare, and F were not available, you'd
still be rebooked in Y (or you could wait until the next available flight with F whenver that may be). And I'm not sure you'd get much compensation, if any, since you already flew F on the first leg and there wouldn't be a fare differential for Y on the second leg AFAIK.