The Service Broker endpoint is in disabled or stopped state - AoAG - SQL Server 2012 - 15 minute interval
According to this link, 


  It’s a default behavior. The message will show when AlwaysOn
  availability group Listener is created and SQL Server binds the
  Listener’s IP dynamically. There is no method to suppress the message.
  These messages are informational message and do not cause any harm and
  can safely be ignored.


That link also gives a query to see which databases do and do not have brokers enabled:

SELECT is_broker_enabled, name  FROM sys.databases