That's a totally valid question that I have thought a great deal about. In broad strokes, no. The underlying idea, of a fantasy city connected to a variety of planes of existence, is indeed clearly inspired by Planescape. The content within is quite different however, focusing on issues of family, culture, identity and language. It doesn't include any of trademarked content, the trade dress is completely different, the underlying system is not D&D, and none of the Planescape races are included.
I openly encourage folks to purchase a copy of Planescape if they haven't done so yet, because I love that work. I have done the same with the other inspirations such as the comic Saga, Kill 6 Billion Demons, Planarch Codex etc.