Must a school inform parents and eligible students if the school non-consensually discloses personally identifiable information from their education records to a community-based organization to which the school has outsourced an institutional service?

No.  While there is no specific notification requirement regarding disclosures under the exceptions to consent, FERPA does require that each school or LEA annually notify parents and eligible students of their rights under FERPA.  34 CFR § 99.7.  As a part of the annual notice, the school or LEA must include in the notification a specification of the criteria for determining who constitutes a school official and what constitutes a legitimate educational interest.  34 CFR § 99.7(3)(iii).