Comentário oficial
The default order in a playlist is, and always will be, the order in which you added them to the playlist. If you want to set the order to be by date added (to the collection), simply show that column if it is not already visible (right-click at the column headers, tick Date Added), then click it once to sort the playlist by Date Added ascending. To reverse sort with the newest on top, click it again.
Next, right-click any of the column headers and select "Renumber Track Order" and this will now be the new order of the tracks within the playlist when it is exported to the USB device.