One of the main reasons the Gonzaga Bulldogs made the NCAA championships is through the strength of the front court, specifically Przemek Karnowski and Zach Collins. Neither of those players will be with the squad next year.
Karnowski is graduating, and Collins has declared for the 2017 NBA Draft. On any other team, this would be quite the hole to fill. For the Gonzaga Bulldogs, they might not be able to fill it as high, but they still have the personnel to make it work, albeit, in a slightly different format.