To be strictly fair to the specific time frame of post-rampage attitudes, even if it is unfair, they did see an ogre "go crazy", rampage into a festival of people and explicitly kill 3 beloved pokemon
This kind of reminds me, actually...did anyone else think that Ogrepon we interact with might be a sort of ghost/zombie situation? It was one of the first things that came to mind when it suddenly showed up. Like, Kieren had gone to that outlook alone for years but never saw it. Meanwhile the grandfather was surprised to hear it had been sighted at all.
Long lived Pokemon are nothing new for the series, but in the same DLC that had 3 explicitly 100% dead Pokemon come back to life (seemingly via Kieran) and then the later part of the DLC having the area where the man laid the crystals (effectively on top of the area ogrepon lives) mentioning sometimes seeing the souls of the dead...
Problems against this of course being:
-The revival of the Loyal 3 was significantly more flashy & ominous
-Kieren's downward spiral & more toxic personality has an implication of an outside force (see again: the more elaborate revival of the loyal 3) that only came into effect after the festival
-No real reason given for why Ogrepon would "come back alive" in relation to a near by battle (it doesn't seem especially hyped for it, inherently and seemed to avoid conflict at the festival)
-Occam's Razor: yeah sometimes pokemon just live a long time. Literally this DLC has an ancient Ursaluna still around and kicking. It's like the different attitudes of past & present, the simplest explanation is the right one and just because there's weird magic wish granting crystals and peaches going on doesn't mean they're involved in everything.
but never the less it came to mind when I first saw it show up.