The book helps to explain retroactively why the Migrant Fleet chose when they did to try and take Rannoch despite the threat of the Reapers.
In Mass Effect 2 Tali mentions that there's a group of quarians who believe they should give up retaking their old homeworld and find a new one yet this is not brought up in 3. If the quarian population aboard the ark makes up the entirely of that particular faction then there would be no more opposition to an attack on Rannoch.
The fact that a statistically significant number of quarians have left for a six-hundred year and 2-million lightyear journey to another galaxy. Suddenly the idea of retaking the quarian homeworld doesn't seem as much of a daunting task in comparison.
The quarian Pathfinder is an anti-AI hardliner, so much so their SAM is pre-emptively shackled to stop it being a true AI. That's going to make conversation with the other Pathfinders tense, since everyone else gets on with their SAMs (assuming that the quarian Pathfinder doesn't suffer the same fate as Alec, Ishara and Macen first).
Fridge Horror:
The novel ends with everything apparently ending relatively well, the ship intact and on course for Heleus, with no mention of the "stay the hell away" message Ryder ends up hearing. Because there's still another thirty years before the ship gets to Heleus at all. Which raises the question of what the hell the Keelah Si'yah has run into that could be worse than that virus.
The ship's complement has batarians onboard. Through Andromeda, it's noted that several humans in the Initiative are vets of the Skyllian Blitz, including one Sloane Kelly. If and when Ryder finds the Siyah, things are probably going to be very awkward...
The angara probably aren't going to be too taken with batarians either, come to mention it, especially since one e-mail found at Podromos notes there's enough similarity between kett raids and batarian slaver raids to hit a veteran's Trauma Button.
If the captain of the quarian Ark is capable of hiding their pants-on-head level insanity well enough to get through the psychological screening the Initiative supposedly has, just who and what else has managed to slip through? The novel does mention that with the minor species, recruitment standards were lowered, but just how low had they gotten?
The lowered standards for recruitment probably explains how head cases like the two Ex-Cerberus scientists, criminals like Kalinda, Merriweather and Aroane as well as remorseless killers like Axius and Mallox were allowed in.
Quetsi's plan already had holes in it to begin with, but even if it'd worked on arrival in Andromeda, everything would've fallen apart anyway. Even assuming someone didn't figure out a cure quick enough, the angara would've taken one look at all the aliens dying of a horrific plague and told them to get lost, or just stayed away. The krogan probably wouldn't have been happy with it either (especially since it's hinted Nakmor Morda actually likes humans). And sooner or later someone would notice the suspiciousness of a horrific virus that spreads across multiple species just conveniently showing up with the newest Ark. In fairness, Quetsi is clearly long out of their tree.
The batarians are mentioned to only have a few hundred onboard. Assuming none of them died from the virus, and that the batarians reproduce at the same rate as humans or quarians, they don't have the numbers to keep up a viable population for a few generations.
