NPC Spawn Issue: Mammoth in Surefall

[Palemoon]

post patch, Ive sat around the waterfall waiting for Mammoth to spawn at 3am (per patch notes), and he never showed.

Next 2am rolls around, and I kill the bears around the waterfall area, poachers too, and then see if Mammoth shows up at 3am with the spawns cleared. He dosent show up.

Maybe I read the patch note wrong?

p.s. I always thought some of the mobs in the bear caves would go through spawn/despawn cycles, includeing Mammoth and his PHers. Is this the case? Can't say I've noticed anything depopping on their own yet.