As long as the turkey has been frozen for the entire 1 year then the bacteria should not have grown on the frozen turkey.
The frozen turkey that has been frozen for 1 year may not taste as fresh but since it was frozen the turkey will still be safe to eat.
I sometimes buy turkeys on sale and then freeze them for 1 to 2 years and eat them at anytime of the year.
So yes the turkey is still safe to eat after a year frozen.