Playing a difficult schedule certainly prepares you for tough teams in the tourney and given that Gonzaga is in the WCC they need to do that. But Gonzaga consistently plays one of the tougher non-conference schedules and this year they played West Virginia, Clemson, Oklahoma, Davidson, Washington State, Illinois, Kansas State, Baylor, Oklahoma State and Butler. They are clearly trying hard to schedule major conference and quality mid-major opposition. So this doesn't really apply to them.
Anyway, it's one game and stuff happens. This game was decided by Wichita State going 14 for 28 from 3. If the Shockers shoot their season avg of 34% from 3 then they make 9 of 28 and score 15 fewer points on those 28 shots and lose this game.