Ten years have passed the Main 6 all have formed Families. Twilight strolls through her Castle as a new Room appears.
Due to the Castles connection to the Tree it is a Room perfectly designed, for the Cutie-Mark-Crusaders.

This is my Headcannon, why the Cutie Marks of the CMC's were surrounded with those of the Mane 6, at the Episode "Crusaders of the Lost Mark"

Contains, Hinted: FlutterCord, FlashLight, SoarinDash, CaramelxApplejack, ButtonBelle, CheesePie, RarityxOC