Originally Posted by
Horadrim
Likely that the data for cutscenes, including NPC models are all stored in the zone where the cutscenes take place. Which is why cutscenes start without needing to load first, as they are included in the loading process for the zone itself. To create a single zone that can load and display all cutscenes in the game --- every NPC, Monster, and character model included in a cutscene would have to be added to a single zone in addition to all of the data related to the the choreography for that zone, not to mention replications of the original zone in which the scene takes place itself. The amount of load of not only duplicating all of this superfluous data into a single, new area as well as the process of loading it each time a character enters this zone would be massive.
Just my theory.
If you consider the fact that all of the cutscenes run in the game's in-game engine, using in-game character models that are just choreographed it's not a bad suspicion as to how they put the system together to be workable on a PS2. Maximizes pre-loading in a big way.