Automating Slack messages with Hasura's cron scheduler and event triggers involves setting up triggers based on events in your application and scheduling messages to be sent at specific intervals. This can improve communication by sending real-time notifications and personalized messages with dynamic data from your application, and streamline workflows by automating routine tasks. Hasura's powerful GraphQL API and seamless integration with other systems ensure scalability and reliability, making it an effective way to enhance productivity in your organization.