@Riot A question about Katarina

Hey there, a small question about Katarina. so if you go into her champion preview in the client, click on the abilities tab, and click "CTRL 1" she says "killing is my duty, fun is yelling surprise!" even though her joke in game is "If you run, you wont see me stab you!" is there a reason behind this? because currently that is the only way i know of to hear that quote, and i didn't even know it existed until today haha. I think it would be neat if you put it into the game, but even an explanation would be cool. thanks :)