Does the Pokemon World Tournament work like the Battle Frontier/Tower/All those in that you don't get the Pokemon you see on your PokeDex?
You don't get the Pokemon you see in your dex. So yes it's like the battle frontier.
They don't specify the world championships. But they say everything else. So if you put 2 and 2 together. Also you don't fill up your pokedex if you battle another human. Same on wi- fi and on battle subway, the battle institute and c gear battling.