I don’t want to speak for Smith, but I see in that page a real tension between their valuing their history and present as a womens’ college, but also wanting to be as inclusive as possible of nonbinary applicants.
And I only have a passing acquaintance with this issue, but my understanding is this is an ongoing discussion at these schools. Are they just excluding men? In that case nonbinary needs no qualification. Or is there something more affirmative that they are doing, and if so how do you describe that?
Anyway, as you point out, people have to be comfortable with how their college is approaching these issues (indeed, I would say that is true for anyone, not just those who identify as nonbinary). I do think if Smith is otherwise a desirable college for a nonbinary person, they might want to reach out to Smith for a direct conversation about this issue, including a pointed discussion of what Smith means by terms like that.
But obviously then whatever Smith says to them is something they have to evaluate for themselves.