Frank turned down a very talented team. Here is what is waiting in the wings after the 2015-2016 season. Rankings according to ESPN top 100...

2016-17
Emery- 45
Haws- 51
Dastrup- 95
Mika- 28
Childs (offered & leaning toward BYU)- 55

2017-18
Emery- 45
Haws- 51
Dastrup- 95
Mika- 28
Childs (offered & leaning toward BYU)- 55

2018-19
Emery- 45
Haws- 51
Dastrup- 95
Mika- 28
Harding- 99
Baxter- 53 (rivals)
Childs (offered & leaning toward BYU)- 55

Assuming Jackson doesn't go on a mission and is a one and done, he will play only in 2016 for Duke. BYU vs. Duke on a neutral court would be a great game, if the Cougs had Frank, the advantage could be to BYU. One certainly could argue that Duke might be more talented than BYU for the next few years... but not by much.

When Jackson is long gone, and playing in the NBA, BYU will still be playing great ball, and with the pieces around these top 100 players, they should be consistently in the top 15.