u/Unable-Brilliant-552

I've had this thought for a while now and I just discovered this sub, so I thought it would be a good place to bring it up. If the protagonist of D/P/P is the same as the one who got sent back in time in PLA, where did their Pokémon from the modern day go? I would imagine that if Arceus wanted Dawn/Lucas to save the timeline, it would want to send their Pokémon that they've trained for combat already with them. I know I might be overthinking this and it's probably just because having a full-fledged team from the start would kind of defeat the purpose of the game, but I was wondering if anybody has any ideas about how to account for this lore-wise?