I feel we are going in circles. You already agreed earlier that the NPC personality modelling cannot give comprehensive answers. So this was about a situation where you have already considered the personality of the NPC and feel it could go either way.
Yes, we are going in circles. Because whether it can go more than one way isn't the point. It's that the GM's decision making is not about achieving a specific outcome.
If the GM felt that the NPC would flee.....but thought an exciting battle would be more memorable, and so he has the NPC decide "Enough running....all my plans have lead to this moment! I'll crush these interlopers!" and shifts what the NPC would do based on having an exciting battle.....then that would be curation as it's being used in this discussion.
NPC flee- decision based on NPC motives and traits
NPC stay and fight- decision based on having an exciting battle for the game, with NPC's motives shifted to suit
It's not the result of the decision that we're talking about, it's how or why the decision is made.
Of course no one is advocating NPCs acting against their personality, that's not what happens in a good story.
Meh, this is so hard to judge. People change their thinking all the time, in real life and in stories.
Yes, you're curating the story. If you're creating the NPC personality on the spot, then your decision to make them a coward is decision about the direction of the story. You're just prioritising your vision of the NPCs personality over a climatic confrontation. Both are perfectly valid, and both are about the direction of the story.
I specifically said based on what had been established. Fidelity to what we already know of the NPC. Not something created on the spot.
But really, either way, there is a distinction, and you're not seeing it, so I don't know what else to say. As you said, we're talking in circles.