Why not? They both knew/know that "Danu Talis had to fall for the modern world to rise."
"And Josh would destroy it." (Page 498).
"In the days and weeks to come, Sophie ... [would lead the survivors] off the sundered island and take them out into the world." (Page 497)
Josh destroyed the OLD world; Sophie and the others saved the surviving humani, who resettled and repopulated the NEW world which came into existence when Danu Talis sank.
Nicholas knew this to be the way it HAD to be, and so did Tsagaglalal, who gave Josh the Codex, knowing that he already had the Final Summoning pages. Josh had the Codex. Sophie had her powers plus the Witch of Endor's memories, which I imagine served as a guide for the new world.
On a slightly different topic:
My grandson was showing me some of the stuff springing up on "Minecraft" -- it reminded me of when I read The Alchemyst for the first time and imagined how detailed one would have to be when creating a Shadowrealm! "Middle Earth" and "Hogwarts" are just awesome!Fixed your quote tags ~ Moviebuff