This year's prestige shop will include an animated K/DA Kai'Sa emote, as well as grab bags for Pulsefire and PsyOps. Details on percentage drop chances and loot content are in the article
I wonder if the animated emote will actually be animated this year, since the Ahri one was teased up until and shortly after release as "Animated" then they pulled it from the shop and renamed it to remove the word "Animated"