Odd, I don't recall them promising this outright, and I can't seem to find any interviews or articles where they claim the game will have a standard solar system model before launch, or that they'd add it after launch. Do you have a link? If they actually did say they would change the solar system design away from the 'postcard' style towards a more realistic one, I'm going to keep holding them to that.
Sean talked about it in the
Atlantic article in February:
“Our day to night cycle is happening because the planet is rotating on its axis as it spins around the sun. There is real physics to that.”
In March of this year, PlayStation Access also
confirmed these types of orbital mechanics (around 1:30). Obviously they were told that by Sean, and this wasn't a two-year old video, this was pretty close to release.
Neither of those things are happening. The planets don't rotate on their axes, the moons don't orbit planets, and the planets do not orbit their star. Hence the day/night cycles which number in the minutes instead of hours or days. In fact, I believe the star actually orbits the planet cluster, which provides the illusion of rotation. And the star is not actually a star, it's just a light in the distance which you can't ever reach – if you try, the coordinate system will eventually go haywire and things will glitch out.
That is the only thing I truly ever felt deceived about. I was sold on the idea that NMS was a proper universe simulation, within reasonable limits, but it's actually just a collection of nicely arranged props.