I think it's a great fight don't get me wrong, I'm just confused as to why they won't do this with other pairs of clear top contenders, even when one is coming off a loss and still the 1 and 1a and Mendes fighting for a title/interim 3 times in less than a year and a half is the repetition people gave Frankie and Cain/Zuffa shit for. I don't see them changing to this in all divisions (even though they probably should) they usually want to have separate clear paths and claims to the title for spare guys in case of injury. If Luke dropped out for some reason, Jacare would not be argued as a weak replacement, if he had lost in this type of fight, it would be replacing off of a loss or with a guy who didn't have the decisive win to make it in their position. There's risk in this if injury crops up...
I think they fight at some point regardless of this, the best do fight each other all the time, it's what titlefights are.