Paldea will impact Briar's story but not her present, it will impact her past. :] As you may or may not know, Briar, apart from being a scientist, is also an engineer. She studied engineering in Paldea after finishing her studies in Kalos.

So my idea was to give her a very small Paldea arc in her early/mid 20s, right before she joined Team Flare. She moved to Paldea to study engineering, and with her college friend Jacq, they would go on a small adventure in the region. As I don't know anything about the story of Paldea, this section is mostly a WIP but I'm planning on making her have some sort of story, encounter or something related to a Legendary Pokémon in Paldea (not necessarily Miraidon or Koraidon, but maybe another legendary in the region), which ends up sparking that interest Briar has in Legendary Pokémon. Nowadays, Briar is a scientist who specializes in Legendary Pokémon, but where did that start? Well, once I play SV you will see the answer!

So yeah, this little Paldea arc happens after she graduates as a biologist, and before she meets Lysandre in Kalos and ends up joining Team Flare. I'm very excited to write this arc!!