He did stay at BYU from what I remember. He just decided to focus on school. Maybe we can "bring him out of retirement" kind of like the Utes did with Joe Williams. I don't think that Jakob Hartsock is completely the answer. We really need a 3 and D wing and Hartsock did not show the ability to defend the wing.
However, I believe Hartsock would give us some interesting options that Aytes, Shaw, and Worthington just cannot provide. Dalton Nixon is another kid who could possibly provide that boost. Both Hartsock and Nixon would need to really put in some major work and improve their game.