>>53544152It's neither. The existence of the S/V books and the paradoxes are the direct result of an ongoing time loop. When the professor fucks off into the time machine, they pass all their knowledge of the time machine and the paradox Pokemon onto Heath in the past, who then writes this book and begins the cycle anew. This means that the paradox mons simultaneously never and always existed, hence the title of "Paradox Pokémon".
No, I don't have any proof for this and I don't need to. My headcanon is just as valid as any of the bullshit, half-assed slop writing that the game pretends was forethought.