All the body work remained the same from 16 to 17 on the RG. Which uses the same filler panel tri bar light set up. So I'd say yes.

 

Street Glide will have the dimples for turn signal bar and no tail light. Believe the 16+ Ultras don't have the turn signal bar any more but do have the tail light.

 

Your definitely going to have to look into the wiring . The detachable kit comes with the saddlebag lights for turn signals (built into tour pack on ultra) and a gomer (IMO) looking plate mount. The RGS/SG fender and facia will fit, but they have the turns and brake built into the light bar. The fender, etc will fit, its in the wiring. HD parts does have a CVO style fender/light kit, that shows it will fit the 2016 Ultra, but it will require you painting and its $$$, but may have the wiring figured out for you and it looks nice!! brake/turns are built into the facia like the CVOs...