Maybe a solution would be to put a message in the quest journal to confirm that Minthara will be recruitable when you find her again. At least then the player knows that the plan was correctly executed.
I think this would break my immersion tbh. But everything depends on how Larian would execute it, or if they would even consider improving her recruitment at all.
Yea it would be strange to write that she is going to be recruitable, kind of going against the whole open-endedness and letting the player steer (parts of) the narrative. They could write something more vague along the lines of that she appears to have got away and that you might cross paths again in the future, if they wanted to add some kind of confirmation.
Personally I hope they don't try to force her survival. Other than that I, as a player, knows the game logic and content exists to make it possible, she doesn't feel much different from all the other bad guys you kill who don't get any chance of redemption.
But speaking of Minthara, it's pretty obvious that she is coded differently from other enemies since you can loot all her clothes, including her underwear. And if you knock her out and take a long rest so she wakes up again, she'll just stand in her room naked if you return. Would make more sense if she was gone (and perhaps with some kind of journal entry or voice line that she maybe survived) or at least if the game had spawned some destitute clothes for her to wear
