I know the 25% thing comes off as smart-ass, and it is to a certain extent, but honestly, I don't think there's been some concerted effort to get UK and Duke in the same region. You'd have to go back to 93 for it to even be relevant, and since then, UK and Duke have been in the same region in 94, 98, 01, 05, 12, and 14. 6 out of a possible 21 times, not much higher than the 1/4th that randomness would predict.
94 was the one year where I really thought the NCAA went out of its way to (attempt to) create the matchup.
Edit-Forgot 07. But UK was an 8 that year, Duke a 6, so the odds were heavily, heavily stacked against them meeting