@Knixon said:

In the early first-season episode "Battle Lines," before the Kai goes through the wormhole and becomes essentially immortal/dead, she gives her necklace thing to O'Brien for his daughter.

Do you suppose that was meant as some kind of foreshadowing that they wound up deciding not to pursue?

I wonder what they might have been planning?

No the script said so

Yes, well, the scripts have foreshadowed in the past and then changed. Such as the alien parasites things near the end of TNG season 1, that got retconned (rather badly, I think) into being the Borg.

Well the aliens from Conspiracy would be an interesting foe for a Trek show that takes place in the future.