According to this recent interview with Honda, the 2.0L turbo will start mass production in the US during March. That would suggest the SI is coming this spring.
http://wardsauto.com/engines/honda-powertrain-overhaul-targets-weight-emissions?page=1
WardsAuto: Honda introduced the 1.5L unit in...
Our friend HondaPro Jason has shared his speculation on the CivicX Si model, gathered from his own intelligence, sources, and rumors. Note: these are not officially confirmed by Honda in any way.
Si Model Year: No 2016 Civic Si model year. It will be a 2017 model year.
Release: Late Fall 2016...