It helps paint more of a picture of the player, but it isn't a deal breaker.
I thought Parker was a top 4 pick before today's game, as well as after the game.
The tournament probably helps players later in the draft, even in that they become a marketable name, to sell to the fans/media. Guys like Payne on Michigan State, Harrell on Louisville, Johnson and Hollis-Jefferson on Arizona, etc come to mind.