As Shahidi mentioned in her talk with The Hollywood Reporter, Grown-ish is, indeed, a show with more edge than Black-ish.
Grown-ish, however, is pushing the boundaries more on not only what topics are covered (like drug use) but on how those stories will be perceived by the viewers, since everything will be presented through the lens of people who are still essentially kids.
While that series has been known to handle some heavy topics, it tends to do so in a way that feels safe for the audience, and that’s largely because the story is told through the eyes of an adult.