Based on the SMS audience etiquette principles, when performing a bulk import of existing contacts who previously opted in, you must still ensure you have verifiable, explicit consent documentation for SMS marketing before sending any message.

This statement is true. Even when importing existing contacts who have previously opted in to SMS marketing, you are legally and ethically obligated to have verifiable, explicit consent documentation. This documentation proves that each contact specifically agreed to receive SMS messages from your organization. Without this, you risk violating privacy regulations (like TCPA in the US or GDPR in Europe) and damaging your brand reputation. Simply having a contact in your database or having them opt-in to email marketing is not sufficient for SMS. False is incorrect because the requirement for verifiable, explicit consent is a fundamental principle of responsible SMS marketing, regardless of how contacts are acquired.