Imaro
Legend
Sure...its like having Ragnarök in the future of the setting.
Hmmm...ok
You can play way before the event, using it as a foretold DOOM, or
You could do this without its destruction being pre-ordained in s published product.
Darksun campaign conclusion: The Black Hole is starting to shred the barrier around Dark Sun, can your players use this window of opportunity to evacuate survivors off the world before the end? Will this survivors (due to black hole time shenanigans actually be the founding races of the cosmos, i.e. Dark Sun was the Prime World?
But do you need an official ending for this? I guess what I'm getting at is what is the benefit to the setting having meta plot for those actually playing in it?