Has SEO changed over the course of 10 years? Yes, drastically.
Will it continue to change over the next 10 years? Yes, drastically.
As Matt Cuts said, the only constant is change. Yet the change is EXACTLY why SEO is a valuable longterm career. Business will always have a need for consultants to help them optimize their online presence, no matter if it goes through Siri, Google Search, or Facebook.
Have no fear guys, Leo needs to make controversial speeches so he can get up on the podium. It doesn't make them true.