Like IT sector, traditional animation is in crisis. At the moment 3D is the thing and it will take a while, until suits get it, that it has nothing to do with the mouse or pencil, but with the story and how you present it. Some stories are better told in CGI and others in 2D.
Those 2D artists who can learn and adapt to 3D stuff, will survive much longer and later on, when 2D artists will be needed again, can switch back and forth.