Nothing of value was lost. If someone like Bwonsamdi or Odyn is able to figure out a way to intercept souls and put them in a specific realm, so are the Eternal Ones. They can assign someone or do it themselves, they can project themselves in the Arbiter's chamber and you don't even have to be an Eternal One to do that, so they can just set up a council or something. Or maybe the First Ones will get involved and will realize what a messy and unfinished design they've left.