Pacquiao vs Khan instead of Horn: Did Bob Arum get put in his place?

[U.K. Fight Fan]

I can see Horn going the distance. He's bigger than Pac, and Pac hasn't KO'd anyone in years. I can see Horn winning a couple of rounds just from pure effort. Pac doesn't work the full 3 minutes of a round anymore. Even at 38 though, Pac is a whole other level. Pac by UD with possibly multiple knockdowns.