If you want to get into semantics yes Capstone was a "program", a program to develop advanced navigation avionics.  ADS-B has been around for awhile and it's already being used by the commercial operators in rural Alaska, I believe the 2020 deadline is for all aircraft including private planes.  ADS-B is a separate program and less capable then Capstone was in 2006.  A lot of accidents would have been prevented over the last 11 years if Capstone had been fully implemented.