These holiday events have been a complete miss. You had mentioned in the Q&A that you have a team devoted to reskinning a single event to facilitate each holiday (paraphrasing slightly.)
Currency is fine, but why not just encourage social/team play by adding currency drops to loot in OPR, Arena, Expeditions, and Wars? This would encourage players to partake in already existing content that is underperforming while assisting in player retention by increasing the number of players in these pools.