I feel like the movie did a good job of leaving the world’s ultimate reaction (after shock) open-ended and making that the point. Of course the cynical and perhaps most realistic reaction is lots of people not caring, and even rooting against the aliens. (Though I think “90%” is hyperbolic and too cynical.) The movie’s ask of the audience, though, is to listen and care, even if it requires reassessing your prior assumptions and beliefs or whatever.