That is a very interesting paper and I only read about half of it, but so far it looks like is says that we will definitely leave a signature on a multi-million

That is a very interesting paper and I only read about half of it, but so far it looks like is says that we will definitely leave a signature on a multi-million year timescale and while it explores the possibility of the Silurian hypothesis, it says that it's unlikely, but lays out some possible markers if it were true. I think it's a good paper, but one that says the opposite of what you believe. Also, this paper explores markers of human-like civilizations on million year timescales. It would not touch in any way their continued existance, that is inferred in your comment.