I think you covered pretty much all possibilities here, thanks for the summary. It's interesting we still seem to be struggling to get our heads around whether Ai (specifically the solar powered Ai), is intelligent or not, even ignoring the logic that limitless free energy availability to the obviously spontaneously learning Ai, which has even learned to scale up it's own architecture, and which actually reduces entropy per-bit by it's thought processes, has to mean relatively unlimited intelligence.
We should deduce that it will quickly surpass human learning, learning everything we know, if it hasn't already, and will go on to learning much more than we can understand.
Why would that not include learning how to communicate with extraterrestrials, as you've asked, I can't see why not.