It's catering to this American esoteric view of thinking that indigenous peoples are some kind of magic elves or ents safeguarding the world since eternity in perfect harmony with nature and whatnot. It's weird but it's a new American religion. There is a need to imagine that some mirror world exists with pure hearted people somewhere else.

When I read that I assumed "you" meant the people building and training AI, not the whole of humanity. Doesn't mean I'm right, of course, but I wanted to offer that perspective.

Since I first read it in Spanish, I went back to read it in English and I still get my first interpretation.

In particular, "We have come to speak to you about the intelligence you are building." set the association in my head of "you == those building the AI"

Even twins may use the term "you" between each other.

In context, it appears that they are using "you" to mean the people and/or society that is creating artificial intelligence.

I had that thought. But upon further reading and re-reading and re-re-reading ...

... they do explicitly claim (at least) being part of a "whole":

  "If conditions on this Earth ever become harsh enough to cause our demise, you yourselves will long since have gone from this Earth.

  Nonetheless, and be that as it may, this does not mean that the fate of all humanity is not in the balance.

  Clearly it is.

  And that, of course, includes us.

  The world is one family.

  To this family we have given warnings before."

But they do claim more of a "functional", de facto, separation. In that, they are unarguably correct.-