Defendr keeps a snapshot of your channels and roles and a copy of everything that was deleted in the last 14 days. After a nuke it can recreate the channels and roles with their names, types, categories and permission overwrites; overwrites that pointed at a deleted role are pointed at the recreated role. Messages cannot be restored, and webhooks have to be recreated by hand because Discord never returns a webhook address again. Channels whose names hide them are never recreated.
Example
Twelve channels and three roles come back with their permissions two minutes after the card appeared.