Well, the Yahg were on the verge of chemical rockets if I remember the lore correctly, and had enough contact to know that there had been other species out there, so they could go either way - but if not wiped out, they're probably expanding into the wreckage of the previous Cycle already, and are pretty much tailor made to be Mongol Hordes in Space between their aggressive attitudes and monstrous (to human sensibilities) appearance. Perfect to be second-arc antagonists, in other words. (Assuming first-arc is internal Human politics and dealing with first contact when the alien is a last-survivor blue space hottie who wants human mates to repopulate her species with, plus the minor matter of explaining about the giant space fleas that set up the Mass Effect tech tree to be found so they know what to expect when they sweep through the galaxy killing everyone every 50,000 years, like they just finished doing.)
--
"Anko, what you do in your free time is your own choice. Use it wisely. And if you do not use it wisely, make sure you thoroughly enjoy whatever unwise thing you are doing." - HymnOfRagnorok as Orochimaru at SpaceBattles
woot Med. Eng., verb, 1st & 3rd pers. prsnt. sg. know, knows
--
"Anko, what you do in your free time is your own choice. Use it wisely. And if you do not use it wisely, make sure you thoroughly enjoy whatever unwise thing you are doing." - HymnOfRagnorok as Orochimaru at SpaceBattles
woot Med. Eng., verb, 1st & 3rd pers. prsnt. sg. know, knows