User blog comment:Justarandomguy/Are the Quarians Doomed also?/@comment-1441235-20120318053505/@comment-1653815-20120318055054

Not necessarily. They would still have FTL onboard ships, albeit those systems may be destroyed as well. The mass relays just make things easy, but I could see the races spreading throughout the Local Cluster. Because the Reapers spread from Batarian space into human space in less than a year.