In our unique case, it would have meant we could have exported old DMs from users who have since left the company after a recent merger.
I'm using my example to think forward: an employee leaves due to workplace conflicts, and later (not to intimate this is the path I'm taking, I'm merely walking out the door, as my issue was a mere personality conflict not something that I can seek damages over) pursues civil action, a responsible export and archive policy from HR the way IT departments may sometimes be required to retain email messages for a period of time can be a benefit if the departed employee cites their interactions with an abusive manager for their departure and subsequent litigation.
I'm using my example to think forward: an employee leaves due to workplace conflicts, and later (not to intimate this is the path I'm taking, I'm merely walking out the door, as my issue was a mere personality conflict not something that I can seek damages over) pursues civil action, a responsible export and archive policy from HR the way IT departments may sometimes be required to retain email messages for a period of time can be a benefit if the departed employee cites their interactions with an abusive manager for their departure and subsequent litigation.
Other commenters have referenced this as well.