The selection committee isn't just trying to have a beauty pageant. When teams get in who "should not" there has been a common theme-- they looked like a team that could win some games. The talking heads sometimes get outraged, but those teams have a good history of playing well in the tourney.
The BYU team of the past 5 games is a team nobody would pick to play as their lower seeded match in the big dance. The Zags were playing tough D and BYU was able to create shots and hit get buckets with a hand in their face. Lots of teams wilt under pressure. This team is getting comfortable with it. They have more guys who can create shots on score than most college teams, often 4 on the floor at a time. Recently they have learned how to play tough D. The Zags had to earn almost every point they scored too.
Plenty of people on the committee will want to see this BYU team have a chance in the tourney. The metrics and numbers and ranking will now allow that.
Let's hope BYU wins the WCC tourney and removes all doubt!