Yes, earlier starting games in the East have larger potential (and actual) viewership.
But the late games, which probably are only watched in the west, are still a large strategic prize. And the P12 Is the only conference that can capture that late, west coast, viewership.
I think the appeal of early games featuring west coast teams is something, too. I will only watch a game that is out of my zone, sonto speak, if it is a marque matchup. And that doesn't mean only SEC teams.