Facebook claims that the written word is dying

Are we at a point where our grandchildren won't be literate? Facebook makes a claim that text is disappearing. I guess they have some hard facts to make such a claim, and even if it will take up forward five or eight generations, will new technology come with illiteracy as a consequence? Please discuss. (Makes me feel like I'm in a pulpit.)

Twitter is to communications as haiku is to literature.