What's the point with that quite lackluster story in Endwalker?

[KageTokage]

That brings up a point I'm curious about: Meteion mentions that she has an egg that she's storing souls in so they won't be reborn. Does getting rid of the Endsinger allow the Blasphemies to actually go to the afterlife? The egg thing did crack before the final dungeon.

I think she was referring strictly to the souls from the dead stars she visited, not the people of the Source.

The whole thing with the blasphemies was that it was believed there wasn't anything left of their souls to return to the Lifestream...but then again, Ardbert seemed plenty intact despite his lingering soul being thin enough that the only one who was able to tell he was there aside from us was Hythlodaeus who had exceptionally keen soul sight, so it's hard to say.

I do feel like there's a little side plot regarding that "egg" that's going be covered either through dailies or custom deliveries that's going to play out over the course of the expansion given what happens in the wake of the Smileton dungeon quest, though.