I think this fight makes more sense than some are saying.
Firstly, Tony and Kevin are fighting in October for the interim title. The UFC right now, in my opinion, needs to maximize profits without hurting the legitimacy of their titles. This is a way to do that, because since Tony and Kevin are fighting in October and Khabib is seemingly on the shelf until he can show that he can make it to fight night, having Conor fight Nate in December gets the biggest PPV the UFC can make in at a time where Conor wouldn't have any more deserving contenders ready to fight anyway. This ensures that you get Conor vs Nate for the belt, and most importantly to the purists it does so in a manner that doesn't screw over one of the main contenders.
One question I have is why people are asking how Nate deserves a title shot, but they aren't asking why Lee deserves an interim title shot. I think this is telling, and it shows a bit of the bitterness (justified or not) that some people have towards the way that Conor has been booked. The fact of the matter is that the UFC and Conor want the Nate fight next, and this is the absolute best time to do it for a multitude of reasons. Firstly, as I laid out above it slides it in during a time where nobody else will be available, but most importantly imo is the fact that they want to capitalize off of the momentum from May-Mac, and Conor and Diaz always provide drama outside of the cage and fireworks inside of it. This is a best case scenario where everybody gets what they want, provided Conor defends against the top contender in his first fight after Nate. I honestly think people should be happy with this booking if it happens.