Does Safari restore the previous user profile after a failed upgrade?

Goal: Determine whether Safari automatically restores the previous user profile and browsing data after a failed macOS upgrade, or whether it launches with a new data store.

Safari installs through a staged process that replaces the active application bundle. The installer may revert the bundle on failure, but this rollback behavior is not explicitly documented. WebKit can create a new data store during migration, and an interrupted upgrade might leave a partially migrated store. macOS Software Update does not guarantee rollback for application data.

Because Safari's recovery logic is not exposed to developers, the exact decision point and outcome remain unclear. Behavior may also differ across macOS releases.

Does Safari restore the previous profile after a failed upgrade? If not, what conditions trigger a new store, and is there a supported way to recover the pre-upgrade data store?