Thoughtful meta, thank you!
I think the motivation behind writing little confirmation of whether the Queen will be able to resurrect or not after the game ends is because all the dialogue happens within the reign of the Dark Queen. Before it's over, before the status quo ceases to be, it's still bound to treat her capacity to change as an unknown.
You're absolutely right that the Queen's fate is left to the player; to their understanding of who or what she is and how metaphorical death is in this world, to their beliefs about change. It's a fair point that this uncertainty has potential to come off as a tad grim, perhaps moreso than I expected it would. Still, that freedom has resulted in a wide variety of interpretations, which has been fascinating for me and hopefully valuable for the players.