They lost too many guys. I know they're in the SEC yada yada but still. They lost a lot and they don't have anything great for QB play. They're going to want to run it and that's BYU's strength.
I'm not sure they'll even be a top 2 opponent in toughness, but the win would still go far like you said. I'd still love a UCLA win first though. That's very important for CA recruiting, which I think is BYU's best recruiting base.