BYU plays an unranked team in whatever bowl they get.
Beating Oregon wouldn’t be enough to justify jumping BYU right now, but beating Oregon and followed up by beating Ohio State or Iowa probably would be. Even if BYU wins their bowl, a 4 loss G5 like UAB or a 6-6 LSU team does little to nothing when the teams ranked around BYU will all be playing top 20 opponents