Rupp has rarely run well in the heat. But still, a good real race out there for a change instead of a tempo.
Meaning, that sit-and-kick has its limits. Also, it is time to accept that Rupp is older, maybe he has too many miles on his legs, and he is getting slightly slower. This happened to Lagat, who learned to handle his slowing down with age extremely well. Rupp doesn't have the same racers mentality that Lagat has.
For Rio, Rupp wil be (within a few months) the same age that Mo was when he won double gold in London; I don't think age is a factor quite yet.