I don't have the whole story as to when and how this stopped being a requirement (1990s?), or if it was ever a true requirement, but in U.S. DoD aerospace today, Ada is uncommon. I'm not sure of any new systems developed over the past 20 years that are based on Ada. Perhaps some of the avionics suppliers like Honeywell or Rockwell Collins that historically used Ada still do, but I don't think most aerospace prime contractors do today.
The prevalent U.S. Government view is that the industrial entities that implement systems should have the latitude to decide what they want to use. For DoD systems, they would just be expected to have the DoD conduct reviews of their software/system design. [Sadly, such reviews vary wildly in their quality and how much companies' feet are held to any fire.]
Keep in mind the FAA requirements for civil aircraft certification are different from DoD's airworthiness assessments. And then launch vehicles and spacecraft are assessed/certified on a different basis than aircraft.