And as viewed internally by the real-world creators and enactors of that fiction.In the fiction as viewed externally by real-world viewers, yes; because it's been set up that way.
Well, of course not, their POV is dictated to them by those creating the fiction. The villain or foil or extra will not behave as if they knew those were their roles, but they will behave in accord with them, none the less, because both their actions and their imagined perception & beliefs are imposed upon them by their creators.But as viewed from the POV of a character within that fiction? No.
Why, when no one will experience the game from that PoV?That character would have no way of knowing any of this - it would just carry on living its life. And it's that viewpoint that I use when looking at game/system/world design
The players will know who is a PC, who an NPC, and often have a good idea of what sort by how the DM presents them. The DM of course, knows these things with greater certainty.
The characters in question are all-unknowing of their own role & nature, as they have no independent knowledge of, perception of nor control over their own being. They will know, perceive, believe what they are imagined to.