Nate Diaz just weighed in at the accepted weight of 171. That's prettily a huge gap for making it catchweight and there's little to no time for Khamzat to cut down all that mass. Only miracle now can make this an acceptable match. I hope he loses at least 4 or more pounds in a matter of moment. Weight cuts usually have catastrophic consequences on a fighter's performance because of the extreme stress a human body can handle.
I also think Nate would disagree with that kind of decision. Come to think about his final fight in the UFC where he fights a monster too big for his size, he might find it evenly more disrespectful.