All the author is saying is that it might be possible.
No; he doesn't merely say that it "might be possible." He says that it will happen. In fact he's so sure it will happen that it's basically inevitable. So sure that he takes great pains to say so, in bold letters (hundreds of pixels wide):
Which is to say: he makes an outlandish claim in the title, in order to get us to read what he has to say; then meekly backpeddles away from that claim in the body of the article.
Generally the editor writes the title. Regardless, the title isn't very controversial; "superintelligence" isn't well defined and it's certainly possible we could have humans with greater than genius IQ. It was the "1,000 IQ" claim that isn't certain, since it's just a simple extrapolation we don't really know how all of those genes would interact.
No; he doesn't merely say that it "might be possible." He says that it will happen. In fact he's so sure it will happen that it's basically inevitable. So sure that he takes great pains to say so, in bold letters (hundreds of pixels wide):
"Super-Intelligent Humans Are Coming"