To be clear, you are not suggesting that Cyanobacteria originated from extraterrestrial origins. But when it evolved on earth, it then wiped out all non-Cyanobacteria?
When cyanobacteria evolved, they filled the world with molecular oxygen, which was toxic to most of the other organisms on Earth. The cyanobacteria could cope with the O2; so effectively, they terraformed the Earth into a place they could live, at the expense of the organisms that were doing very nicely, thank you, until the cyanobacteria turned up.
I don't believe that life travels between stars.
It can't happen by accident; it has to be done by a sophisticated civilisation. The only evidence I have of such a civilisation is ours, and it's only been able to launch space rockets for a few decades. And our civilisation was living in caves just a few millennia ago. I have no reason to believe we are more than a flash in the pan. I feel sure that in a few more millennia, if we're still around, we won't be interested in interstellar probes we fired-off in antiquity.
Most, not all were either wiped out or survive only in small anaerobic niches. It was a mass extinction.