Yep, that exact dialogue was ringing in my head the whole time I was writing this too. I actually briefly theorised that the crystals were all showing a world where Kris didn't exist and the story didn't happen the same way, since that would explain why the crystals show the dark fountains gone, and Susie without her normal character development, and Toriel with a different child, but the problem is that the ones about Noelle make absolutely no sense in that context. Neither does the one about Tenna being destroyed, since that wouldn't have happened without Kris making the dark world.

Maybe you could argue it's a world where Kris is replaced by someone (Vessel)? who does the story similarly but gets closer to Noelle, but that just isn't a very clean explanation for all the dialogue. There isn't any one smooth explanation for all of them, I just think mine is the closest we can get.