Ngannou has actually earned his rematch in the HW division in my opinion. I don't believe anybody currently has a better case than he does for a title shot - 3 first round knockouts in a row, 2 against former champions, in less than 4 minutes combined? Says a lot. The division is pretty "meh" right now too. Not many win streaks happening at the high end that I'm aware of.
LHW is very stagnant at the moment. Jones has pretty much cleaned out everybody in the top 10, and there isn't many new up and comers who deserve a title shot. Corey Anderson and Johnny Walker are both on 3 fight win streaks, Walker with 3 quick 1st round KO's, and they're set to face each other. The winner of that should probably get a title shot since neither have had one yet, but Reyes is actually on a 5 fight win streak and set to fight Weidman. My personal opinion would be Reyes if he beats Weidman, but he's only ranked #8 while Anderson is ranked #6.
Shitty spot for LHW right now, but if I had to choose, I think Reyes is more deserving if he wins because he would be on a 6 fight win streak.
LW? There's no question on what the next title fight should be. If we don't get that fight, we've been snookered.