Eh, sounds then like it'd be best to take this game like a new Coliseum or XD. Well, this is basically a new entry for veteran Go players instead of the core RPG base (at least the GCN games can transfer to cartridges). I don't expect any Pokémon obtained here passed onto Gen 8, unless the hidden Pokémon Go caught text in Ultra Sun/Moon might play a role.
Also noted that Alolan Mons will be featured in PLG and the "special" Pokémon given is brand new.
Spoiler, click to toggle visibilty