Hello,
No, changes like that should not affect the CustomerSyncService. The main use case of service is intended to keep the data structure of the account in sync if there are multiple entities that access the account. For example, you can grab a list of changes since the last time you looked at the account and update your local representation of the account to match the new canonical representation on the server.
Statistics and read-only attributes that are not settable by any users should not trigger any change in the CustomerSyncService.
Regards,
Mike, AdWords API Team