He is saying what they told him to say. They want another rivalry. Of course gap between the two rivals is too much to even consider them as such, but same with Cristiano and Messi... yet here we are.
Good player I seriously hope this doesnt go too far and he becomes unlikable. But I dont think that is going to happen
Just hope Yamal doesn't embarrass himself like this or like CR7 did his whole career. He probably will, doubt he'll be humble long. Do the talking on the pitch.