https://www.youtube.com/watch?v=AQUfmtXWeao
Take that video for example. In the gen seven vgc part, FSG says that Scizor lost bug bite due to lack of move tutors in sm. So why is this an issue when you can just transfer a Scizor over from gen six? I mean, pokebank was available at this time right? Unless I'm wrong about that. It wasn't also just in the gen seven vgc part. He also said the same in the gen six vgc
Pokemon must have been obtained in Generation VII (display the black clover in the summary screen)
This explains why that transferred Pokémon aren't allowed. The Pokémon has to be obtained in the current Generation. Source: https://forums.trainertower.com/threads/vgc-2019-rules.1222/
However, as of VGC 2020, transferred Pokémon can be used as long as they are adapted to be battle ready (e.g. No transfer moves).
Pokémon need to have either the Galar symbol, showing that they were caught, received, or hatched in the Galar region, or the battle-ready symbol, showing that they were transferred from another game and adapted to battles in the Galar region.
Source: https://www.pokemon.com/us/pokemon-news/2020-video-game-championships-vgc-format-rules/
