Tbh, No Mans Sky and Starfield have little in common except being space games. Starfield isn't a space exploration / space sim game. It's an RPG set in space. Starfield has more of a storyline and characters then No Man's Sky, they're different games for different people
Last time Bethesda said anything about the Elder Scrolls 6 they said it was in preproduction. I doubt they'll really start working on it until Starfield is out.