The account plays a critical role during cluster operations and cannot be removed
ONTAP will display an error message if a deletion attempt is made to prevent the account from getting deleted
cluster1::*> security login delete -user-or-group-name autosupport -application console -authentication-method password
Error: command failed: Operation not supported on "autosupport" user account. The "autosupport" user account is reserved for use by the system.