It depends, but here the devnotes are meant to give context to the voice director/voice actor on how to deliver the lines. So in this instance it’s basically to give jaheiras voice actor background into what karlach is going through, and how to talk to the player etc.
Depending on how you interpret the dev notes, it almost seems like they knew they wanted to force a tragic ending, or at least they decided on that after they wrote a possible path to save her, which they voiced (and coded part of) anyway, but then cut the solutions?
It’s all such a mess, and to be honest it feels like the sort of jumble of unrefined ideas you see in a first draft manuscript. She was added very late, after all…