Is there any reason why the Recently Added playlist fails to get imported from iTunes? After all, if you look in iTunes Music Library.xml, it’s defined there just like the other playlists. Saying that Recently Added is a smart playlist doesn’t seem to me to be a valid excuse.
In the absence of such a playlist, is there any way of filtering the Recently Added Music list on Plex so that only the tracks added after a certain date will be shown - and these tracks could then be shuffle-played?