OS Packages make use of the legacy logger by setting logging.dest -

This setting was deprecated in 7.13.0 - #94238 and causes console warnings now. Using the new logging configuration changes the logging format and [1]still logs to stdout (for now).

[1]https://www.elastic.co/guide/en/kibana/current/logging-settings.html#logging-settings

When you switch to the new logging configuration, you will start seeing duplicate log entries in both formats. These will be removed when the default appender is no longer required.

logging:
  appenders:
    file:
      type: file
      fileName: kibana.log
      layout:
        type: pattern
  root:
    appenders: [default, file]

We don't want to break the logging format in 7.x, so it looks like the way forward is to continue using the deprecated logger in 7.x. @elastic/kibana-core does this make sense? Looking for recommendations on how we want to approach this