professor Long way to go before the Duke-BYU match-up could develop. I think it might be an interesting game, but I have watched Flagg a lot and I don't think anybody on the BYU team is a good match-up. Anything could happen, and BYU did beat Kansas by 37 points earlier this year, but imsusledt BYU, if it gets that far, would be over matched by Duke.
Time will tell. Most of the time, match-ups that people think about end up not happening.
By the way, BYU is going to be joined next season by the top freshman in the country, AJ Dybantsa (next year's Cooper Flagg), so they will probably continue to be a force in college basketball for a while, regardless of what happens in the tournament.