I'm intrigued by your worldbuilding, and would be interested to learn more about the other Kith species. (Great word for the concept, too!)
I'm sliiightly dubious about the psychology in play here—I think most of us naturally seek out human companionship when we need it (humans are common on starships when this is set, yes?), and know our own needs well enough to ensure they'll be met, especially if we know we're going into a situation of hardship (i.e. a long space voyage). I also know that our real-world space program vets its astronauts with extreme care to ensure physical and mental stability, and I wouldn't expect future space exploration to take place without a similar level of care. Plus, if we take zero responsibility for looking after ourselves and letting others know of our needs, that's on us and no one else.
That said, individuals are individual. I believe that something like this could happen as an unfortunate collision of personal and systemic screw-ups. I very much like that everyone takes steps to understand each other better and correct their mistakes at the end.
A couple non-story notes on accessibility: I read this on mobile, and it's a good thing, because I got a plain, unformatted version of the text. I don't think I would have tried to read it through the rather small, fancy font you're using. It's pretty, but that sort of thing is best saved for headers. At the very least, consider making the text bigger.
Also, the tags only appear at the bottom of the post. I'm not sure, but I suspect that making people scroll over text that may contain triggers to find the warnings for them may discourage folks who have triggers.
~Neshomeh