The planet should still probably be the site of some mining operations conducted by introverted sorcerers handling their own climate control, and there is occasional reason to use gates for rapid transit across Fairyland, but otherwise Fairyland can handle all their needs.

(Promise discovers, about a hundred years after the Usurpation, that Scadrial is not in fact "the mortal world". The gate she made for the mortal she was trying to help back when Thorn caught her goes somewhere else. She doesn't tell anyone.)

There are minor hiccups and issues; they get fixed. The ex-queen starts calling herself Whisper. Promise and Arcane are adorably enamored of each other. Thorn continues to be a heavily restricted sparrow. Civilization creeps across the Steppes.