Forum:KB:Hollow Alderaan?

Can anyone confirm if Alderaan was hollowed out by an unknown species before human colonization? I read on a starwars.com forum yesterday that in Joiner King some reference is made to Alderaan having been hollowed out by either the Celestials or the Killiks before their evacuation. This was used as evidence in the Celestial mystery, as proof that Alderaan had been intended to contain repulsors similar to those of the Corellian system, and that work was abandoned halfway. Can anyone tell me if this was actually stated?