I admit I haven’t been to the Disney Jr show or Voyage of the Little Mermaid, but we saw the Frozen Sing-along when my son was almost 3, and we all enjoyed it (even my “I don’t like Disney” husband). It’s just a theater where you sit in a seat...no interaction required.
We just took our 18 month old to the Disney Jr. Dance party and she absolutely loved it! There is an area in front of the stage where kids can go to be more interactive with the performers but we sat in the back (everyone sits on the floor) and had our own little space for her to dance. It was great!