I see it as a bone to her clerics, who, given time to develop personal priorities beyond following orders, might have misgivings about either destroying this world or their accidentally getting their nice new meatsuits destroyed before they had a good chance to enjoy them.
"Don't worry. You can be Plane Shifted away." = "Shut up. Don't think. Follow orders. Trust me. (And I might not even be lying. I do not know myself yet.)"