As known from the live streams there is a hidden secret in the game. Well, there is also a banner for it in the universal profile. I think it looks like the prestige emblem. I think the secret is one of 3 things.
1.) It's just once you get a prestiges player
2.) There is a prestiges tier in the xp reward path form once you get diamond 100 or beyond.
3.) I don't have any idea of anything else. What do you all think it is.