It's entirely possible it's a reward from one of the other aspects of the event if you keep reclearing it. Other than the pumpkin hunt, there's:
* Trading sweets rewards
* Costume contest rewards
* The bat/ahriman event rewards
* The costume rewards
* The wake of the lilies rewards
Nothing new's on the vendor, and I did all the pumpkin hunt already. I haven't had the effort yet to pull all the past rewards out of event storage/slips to minimize the effort yet on the others.
Or it could just be not part of this event at all, usually they mention a new item on the actual news article but that wasn't done at all for these. It would make sense for them to be there, though, they don't usually add like next month's login items early.