I haven't played DAO, but do the endings of that game radically change the game universe, making it hard to set-up a sequel?
They radically change Ferelden.
Which we still get to visit in DAI.
I'm just saying that Mike isn't stating much here, other than their typical line about choice and consequence hasn't changed. "There is no canon."
Even if this is never entirely true, it maintains as their guidepost for designing their storylines and worlds.
For me, in Mass Effect, this can range anywhere from:
-literal --> Reapers may or may not be around (or could be rebuilt in Destroy in their own way) and may or may not be relevant (or whatever; something like this. main point is that something gets figured out)
-to --> its all a bloody 'dream' and the reality of things is different from what we directly saw in ME3