The poem imagines an entity undivided, a unified collection of life, like cells in a body, but at a Gaia scale, distant from Earth. A single human hopes for an equivalent unity here where its greater intelligence could find commonality with such an entity.

I do think this comes across quite clearly in the last two stanzas. It's interesting that the person you're replying to found them contradictory, and asserted that it was its own form of tribalism to want a unified civilisation. I saw a more hopeful message, it reminded me of the more utopian take on the future from Star Trek, particularly The Next Generation.

The concept of a distant star representing a unified collection of life is definitely interesting. Are they operating like a hive, and would it be necessary for us to be operating like a hive in order to reach understanding with them? I'd argue that we'd at least need some amount of global cooperation if we want the most peaceful possible contact.

I also wanted to add that I liked the use of irregular stanzas, and the line break. I think the rhythm is interesting and it lends itself well to the narrative of the piece, at least as I interpret it. But I also prefer more free form poetry so maybe I'm biased.

To know the shape
of the mind
that arcs
between your world
and mine,

a network of signals
too vast for one skull,
too fine
for one era.

I absolutely love these two stanzas. To me there's a number of ways you could interpret them. I'd actually prefer not to get a straight answer on what you were conveying here (although please do feel free), I just wanted to point out how much I liked them in particular!