The %ProgramData%\Symantec\Symantec Endpoint Protection\PersistedData folder is not deleted, during a successful removal of the Symantec Endpoint Protection (SEP) client using the CleanWipe tool.
The PersistedData folder houses the sephwid.xml file, which is used by the SEP client to store its hardware ID. This value is used to uniquely identify a client to its manager and is not intended to be removed when the SEP client is uninstalled. Removing this file during a CleanWipe run would cause subsequent installations of the SEP client to generate a new Hardware ID. This will generate duplicate entries in the SEPM database for the same computer until the entries associated with older hardware IDs expire and are purged during the regular SEPM maintenance cycle.