As someone who’s only actually watched Frozen properly one time, I thought they got everything pretty well matchy. On the one hand that’s good because changing things from a movie that’s so recent would have been like blasphemy to many. On the other hand, it’s a weird fit for this show that always does its own spin on things. So basically, damned if they do, damned if they don’t, so maybe they just shouldn’t have.
That being said, leaving the movie out of it, the story they have planned for the Frozen characters so far seems fine. If I didn’t have, “they’re trying to cash in” in the back of my mind, and just looked at them as characters that could have been created solely for the show, I’d say they’ve set up an interesting new story to add to the mix.