Well yes. We are still assuming mostly Thargoids but could be wrong. But your point still works as well. What about AW? Any of those out here? Just trying to point out how we search for life as we know it. If one of their homeworlds is out here then we could find it that way because they likely need a way to sustain life. Maybe Merope is just their beacon star to the nebula?
This is not intended to incite a flame war, & if you want to assume Thargoids & work on that hypothesis fine go ahead, but please do not say "we" are assuming Thargoids because that includes me and IN NO WAY do I think UAs &/or Space Barnacles are anything to do with Thargoids. I can see absolutely NO evidence for that hypothesis (other than, as far as I can see, Thargoid Paranoia). In any case I believe Thargoids, when they enter the storyline, will be friendly (unless they are antagonised).
My own suspicion for the storyline is that the UAs are themselves a low-intelligence form of alien life with similar behaviour to Earth Barnacles; they seed and grow into Space Barnacles which will provide a source of meta-alloys which will in turn provide new materials for ship/equipment development. I suspect the reason for so many downed satellites is that they have encountered UAs in space, the UAs have tried to feed off the satellite metals & damaged them and in the process the UAs have learnt Morse code. This may be pure speculation, but at least it does not include Thargoids!