First of all, in simplyfied theology words, Animals have the pneuma and the ruwach for Humans. Diferent Styles of "spirit/souls"
For what can i understand about ARdenwald its that, Animals (pneuma) died and return to be "recycle" into a new spirit and return to the cycle of life.
So by knowing that, Ardenwald makes sense, since Cenarius died and returned without deeper explanation.
As for the "Souls" in general, we can carry many sins, heroics deeds, nobelty. So depending on how tainted or clean our Soul its, we are recruited or dumped, on the other 3 covenants. One to attone your sins, other to continue serving as angels and the other to continuing your heroic deeds as warrior of the Shadowlands.
So by conclusion... No, we should never visit Ardenwald and probably Night Elves Wisps return to Ardenwald to be recycle. So i believe that the Tyrande Questline that they are going to show us will help us understand why we travel to Ardenwald.
And yes, Wild gods are still Animals.... the same with LOAs, they are still animals, but with a huge amount of spirit power.