I noticed that the Newest Toyboxes tab in Community Content seems to be only listing the most recent toyboxes from the Disney Infinity Team (such as the Poe Dameron toybox), then the WDW project Animal Kingdom boxes. But there doesn't seem to be anything more recent. I submitted a new toybox a couple of hours ago to see what would happen. It seemed to upload as normal, but it's not in community content yet, but that's not so unusual since it hasn't been very long since I submitted.
I'm just surprised that there aren't other new toyboxes listed. I'm afraid this may be an indication that there will be no more toybox submissions.