...race survived in Andrmeda. Seeing as it is allegedly a prothean device, it would seem logical that the Protheans used it to escape the Reapers. In fact, it may even be possible that other races survived there from reaper attacks. Races like the Inosanan who came before the Protheans. This can also be possible due to the technology shared throughout races; the crucible as an example. Perhaps they are all ploting to take back the Milky way from the reapers. When they find a way back to the Milky way, they find that the reapers are defeated, and the council races are in power. This will cause a struggle between generations of different races that once controlled the Milky way. This is, however, speculation. We'll see the truth next year.