Not sure, I guess the idea is that in the film they were saying they faked the space race to get the Soviets to work harder and waste money, but it doesn’t really make sense and I think that’s the whole point. It’s meant to be absurd propaganda.
spoiler
Which is why in the movie, cooper isn’t at all mad that his daughter got into a fist fight with some kids over them believing and denying the original real textbooks which explain how man did actually land on the moon.
The designs probably haven’t fundamentally changed all that much from their older versions.