The developers are careful to point out that if you're one of "those who prefer the eerily beautiful solitude of solo play, Subnautica 2 will still provide that familiar experience, and prove equally as challenging."
BZ really kinda doubled down on the worst aspect of the first game (the focus on the alien race) and killed the best part (the scared and alone vibe), that's not a good sign imo.
The problem is you can't go back to that well repeatedly. We've played the first two games. The unknown is pretty well known at this point. It's like monster horror movies: none of the sequels are any good unless they pull an Alien/Aliens and switch genre to action.