I think this could be its own thread but what the hell, I'll post it here since it's semi-relevant. It's only food for thought anyway.
One interesting thing about the Sinnoh myths, or what you're mostly supposed to take away from the story, is that humans are or were a type of pokemon. Although, as we know real animals are a thing.
http://bulbapedia.bulbagarden.net/wiki/Animals. Initially I chalked that up to humans just having a more glamorous origin than in the real world, which is just being a really smart ape that got too smart. That's standard in fantasy stuff. Then I remembered that the Sinnoh myths were talking about the past. Meaning humans were pokemon. Obviously trainers aren't breathing fire or splitting earth so that makes sense.
Which made me wonder: What are pokemon?
Someone could just say that it's any product of Arceus &/or mew or something like that, which may throw a wrench into what I'm about to say, but the existence of certain pokemon do the same to pokegod. Pokemon is really broad category. We have inorganic pokemon, ghosts, aliens, beings that spawn from things like pollution, and quasi-animals. Obviously they can't all be related to the Arceus/Mew thing.
Maybe a lot of those quasi-animals ARE animals but also pokemon, and that's where I found my hypothesis.
Maybe a Pocket Monster, or just monster, is "any abnormally powerful and dangerous organism". Which means when humans lost whatever powers they had is when they ceased to be pokemon. It's a huge, broad category like UFO. A UFO could be someone's homemade quadcopter or it could be a flying saucer. A pokemon could be a fairy elf or a dumb fire breathing goat.
To make this more relevant to the topic. This would mean aside from Trainer/Pokemon dynamics as said here
>>25040145No organization of any kind would fully base their interspecies relationship laws or rules on whether something was a pokemon or not but rather based on what it actually is aside from the pokemon classification.