The RevertToFlatResponseDto object

{
  "assignments_moved": 0,
  "assignments_deduplicated": 0,
  "assignments_expired_dropped": 0,
  "nodes_deleted": 0,
  "schema_cleared": false
}

assignments_movednumber*
Number of unique (identity, role) pairs reseated at the root node.
assignments_deduplicatednumber*
Number of duplicate assignments collapsed during the dedupe pass.
assignments_expired_droppednumber*
Number of expired assignments (those whose `effective_to` was already in the past) that were discarded during the flatten. Expired rows grant no access; preserving them as unbounded root rows would silently reinstate dead access, so they're dropped. Surfaced explicitly so the admin sees the cleanup actually happened.
nodes_deletednumber*
Number of non-root hierarchy nodes deleted as part of the flatten.
schema_clearedboolean*
Always `true` on success — the schema is wiped from `Application.settings`.