If you are looking for a large-scale festival or "Pack" experience on those exact dates:
Closing Ceremony: A multisensory light and sound experience to ring in the final days of December. 📦 Pack 498 Exclusives Holders of the 498 designation receive: Priority Access: Skip-the-line entry for both dates. Hidden-Zone Asian Edition Pack 498 27-28 Decemb...
However, the reward is a unique "Golden Dragon Lantern" for your main menu hub, which is a rare cosmetic that likely won't return until next year. If you are looking for a large-scale festival