I don't think it's an extra hour on a flight that is the problem. It's how many long flights a team has to take that's the problem. The idea of getting another team out west (say, Portland) is to make the total travel for teams out there easier. Now, Seattle has to travel to Houston and Texas for divisional games. With expansion plus realignment, you can sub in Portland and, say, San Francisco for those cities to make total travel easier. Granted, you still may add long-ish flights like LA (Dodgers) and San Diego, but the time zones are at least easier to handle.