afaik, the characters before looked too cartoonish and glossy along with all of them being similar in overall body shape. Now Marlie looks way different then the rest, and the others all have distinct features that make them much more unique while also still being in the same style as each other.
The reason for the change was that the old generation model was starting to reach the limits in what could be made with it. So in order to be able to make the game better with more varied content the model got swapped out.
