Re-gifted Amumu Icon working again?

During the Snowdown Hextech crafting special, I got the Re-gifted amumu icon that was unlockable by using the candies, and I've had it equipped ever since. During snowdown, if you had the icon equipped it would do a special emote when you would do the mastery emote, and it went away when the event ended. Now for some reason it works again? When I tried to mastery emote, the Amumu emote showed up. Does anyone know why this would be? It might have something to do with the MSI event, but I haven't seen anything from riot about it.