http://www.pcgamer.com/mass-effect-novel-about-the-quarian-journey-to-andromeda-is-coming-next-year/

Despite being the one race in the galaxy that was actually accustomed to living their lives aboard spaceships, the quarians were not included in Mass Effect: Andromeda. The reason, presumably, was so that EA could make a big post-release splash by adding them, along with some of the lesser-known species, in an expansion, something it teased in an Apex Mission in May.   

Whether that was actually the plan was never confirmed, but any hope that it was fell apart in August when BioWare announced that no further "in-game story content" would be released. But story content released outside of the game is a different matter, and so it is that the tale of the quarian journey to a new galaxy will be told in a novel written by Hugo and Nebula Award winner Catherynne M. Valente called Mass Effect: Annihilation.