The article wasn't primarily about the art style. It says Dragon Age has lost its identity as a dark fantasy setting. While I wouldn't go so far to say it's lost its identity, I think he has a point. A dark setting derives its appellation not from the presence of brutality, injustice and moral grey as such, but from *casual* brutality, injustice and moral grey that's present in everyday situations, and of that there is significantly less in DAI than in DAO. I also blame the people who cry "racism" when you can't play a black-skinned character or "misogyny" when rape is presented as widespread in the setting. Not glossing over bad stuff that can't plausibly be absent is another identifying mark of a dark setting, and DAI can reasonably be accused of that. Nothing truly bad happens in DAI outside of the influence of the main plot. It doesn't matter so much since there isn't any city setting where such things would happen predominantly, but it is noticeable.
Compare DA2 which showed the city elves' poverty, or DAO with its casual abuse of nobles' privileges. I see little of such things in DAI.