I've rewatched the fight, and here's my take on it.
This was Dominick Reyes' fight to lose going into the championship rounds. Rosales had it scored 29-28 Reyes, Solis had it scored 29-28 Jones, and Lee had it scored 29-28 Reyes. If the fight had gone to the cards right there, Reyes would have won a split decision.
If he had fought the championship rounds the way he fought the first three rounds, there's zero doubt in my mind he would have been awarded a split decision win, at worst. Instead, he receded into a shell, and allowed Jones to dictate the pace in those final two, crucial rounds.
You don't beat a pound for pound great in a championship fight by losing the championship rounds. When Jones' had his moment against Shogun, he decimated him. When he returned against DC, he kicked his head into orbit. When he got this belt from Alex, he tactically finished a fighter he had severe problems with last time around.
I think Reyes' performance warrants an immediate rematch, and if he is truly the better fighter, then he will leave no doubt, as Shogun did with Machida. Lets see it again this Summer.