First, UConn had no game plan different than anyone else. They just had the people able to do it effectively. Relative to the 3 ball, only Braden was the only person that can come off the dribble and shoot it. Fletch can sidestep with a dribble, but nobody can move 5-8 feet or more and effectively shoot it and so getting a 3 ball shot off has a bit to do with some shortcomings in the players. This normally is not a problem, but since the Tenn game Purdue did not draw the same kind of fouls and since Purdue was not going to the line and removing players off the court and not worried that Zach is going to score effectively against the players you have that are not in foul trouble...why remove your eyes off the person you are defending? Had Zach started removing players, they would have been chancing more players on Zach which would have led to open 3s.
If you had the Boo type of player that could handle the ball and hit 3s on his own it would be harder to eliminate the 3 ball. NW like Uconn had a lot of screens around the arc, but unlike NW it resulted in drives inside the lane where the 3 NW players when healthy hit shots behind the arc. I'm unsure that Purdue not taking the 3 ball or not making any essentially was any worse of a problem than Uconn getting all the 50-50 balls, getting some good boards with friendly bounces and getting inside the lane to score as much as they did. Being better on the D inside the lane would have more than made up the 3 pt shot differential as many of those were off scrambles and such with maybe one or two off of a nice pass