That assumes that the Nomads that novaed Sol (for unknown reasons) are the same as the ones we see in Sirius. Developer documents hint the Nomads were frozen by the Daam K'Vosh, which may place the Daam K'Vosh's disappearance much earlier than (I at least), would have originally put it. The Daam K'Vosh were a vast interstellar civilization that may even have been extragalactic. Even discounting the possibility of the Daam K'Vosh being extragalactic, that still leaves hundreds upon hundreds upon hundreds of sectors apart from Sirius they may have placed Nomads in.
The guy evidently never made it there, since he couldn't have. He would have died of old age before reaching Sirius.