Fact, 2016 is not the last year for Rocket, Triumph made a public statement to that effect, HOWEVER they didn't say which Rocket will continue, so it is possibly the last year for the Touring.
Triumph also made a statement that by 2018 their whole lineup would be updated, that was in 2015. So, Tigers, Daytona, Street and Speed, Bonneville, Thruxton, have all been updated or will be next year. What's left, Trophy, Rocket, Tbird.
Weight that against Trophy already being the most advanced, and newest design they'll probably count it as "updated" already. Then factor in they've said either the Tbird or Rocket is getting axed, and the logical conclusion is... Tbird dies next year and R3 gets an update for 2018.