Previously, you could only see employee DMs if you turned on Compliance Exports, at which point you could download all of them going forward. Now it sounds like everything you've ever written could be downloaded at any time without notice.
So, all of those communications you had with co-workers based on the promise they would be private until you were notified future ones wouldn't be anymore? Now it's ALL available to your employer.
So, all of those communications you had with co-workers based on the promise they would be private until you were notified future ones wouldn't be anymore? Now it's ALL available to your employer.
Surprise!
(This is presumably due to GDPR)