Kindred already in the game?!

Riot just added it in as an Easter Egg. There is another Easter Egg that was added in a few patches ago where you would randomly have the little swirling icon thing for Kindred appear above your head.

That's just a teaser. It's Riot's way of getting the community psyched for new champions by dropping easter eggs so to speak in game.

As the poster above me said, its just a teaser of whats to come. If a champions release isnt in the patch notes, they arent live yet.