Starting March 4th, 2020 Facebook allows only four types of messages to be delivered to your chatbot subscribers outside of the 24-hour window, and these messages should be tagged with specific messenger tags:
Confirmed event updates - can be used to send the user reminders or updates for an event they have registered for (e.g., RSVP'ed, purchased tickets). This tag may be used for upcoming events and events in progress.
Post-purchase updates - can be used to notify the user of an update on a recent purchase.
Account updates - can be used to notify the user of a non-recurring change to their application or account.
Human-agent responses - allows human agents to respond to user inquiries. Messages can be sent within 7 days after a user message.
When building conversations or broadcasts for Facebook Messenger, don't forget to specify the correct message tag in the TEXT block settings.