What is true about platform event messages regarding editing?

Platform event messages are designed for real-time event delivery and are utilized within Salesforce to send notifications and data between apps and systems. Once a platform event message is published, it is immutable, meaning that the content cannot be changed or modified in any manner. This immutability ensures that subscribers receive consistent and reliable data, maintaining the integrity of the event-driven architecture.

This characteristic of platform events is fundamental to how they function. Once an event is emitted, it represents a specific moment in time and the information it carries must remain intact for all consumers of that data. If changes were permitted after publication, it would complicate the reliability and processing of such events, as subscribers might receive different versions of the same message, leading to potential confusion and inconsistency in event handling.

Therefore, the assertion that platform event messages cannot be edited or deleted once published accurately describes their behavior within Salesforce, focusing on their use case in real-time processing scenarios.