This is not a new feature but in regards to any imported files that have missing dates.
Until now all files in the archive without a date, would be placed in the bottom of the timeline.

Now - for imported undated files from the migrationprocess - the archive and the files, are placed in the timeline where the are attached in the correct order. So if an archive/file has missing dates but come from a consultation, the startdate of the consultation will be where the archive is placed.

This is only for imported files, as files there comes from VetNet always have a date.