The exploration gameloop is too hard to fix. The problem is the entire galaxy is already explored. Everyone knows every star, the only thing that hasn't been done is for someone to jump there. And there's no issue with jumping there; it's just putting the time in. Making exploration interesting had to happen from the beginning - the horse has not only bolted, the stall is old and beginning to fall apart.
You know the devs had zero understanding of players and their own game when they said they didn't think anyone would jump out to Sag A so quickly.
The only thing you could do to make explo "interesting" now would be to add a whole bunch of unbelievable things for people to find. And that's fraught with issues too.
Opening up more planet types to land on gives a reason to revisit systems, as happened with the tenuous atmo planets in Odyssey. There are also regions that are currently locked that could be opened up & populated with new content (more lost civilisations, alien civilisations, extinct or populated).
More could be done with on-foot gameplay (not personally bothered about that) and planet terrains shaped by erosion that are more than just a height map would be cool too. All building on the existing foundations.