Is that due to translations? Does the original Japanese expand on the sorceresses/Ultimecia?

I felt like the Rinoa theory was due to missed opportunity to have Ultimecia's origin be explicitly connected to the past rather than just being evil. But the game teases a lot of lore, which can be frustrating but also makes the world feel rich.

I always hoped that a game like Forspoken (didn't play it) would take you through Ultimecia getting hunted preemptively and turning her villain, like a bootstrap paradox.