But if there aren't all the council races from ME1-3 (I NEED A TURIAN SIDEKICK) then why call it Mass Effect at all? Why not *insert generic other sci-fi setting here*?
If it's gonna be in the same universe then the giant robot Cthulhu's that nearly killed all sentient life are kind of a big deal.
I expect them to reuse the races, but the reapers ceased being robot Cthulhu's when Star child nuked the plot from orbit. And honestly, I expect that the remnants of an ancient race mentioned in the survey you find is probably stuff from the ones who made the reapers, so you'll probably get what you want.