The consistency has been leaking away with every generation.Not only is Bellossom a split evolution, when it comes to starters, GF always seem to show consistency with the evolutions when it comes to appearances. I can't see any of it with Mijuthree.
In Gen I, the starters and the final forms looked fairly similar - just bigger (like Bulbasaur > Venusaur).
In 2 there was some drift (Cyndaquil > Typlosion).
In III, a lot of consistency was missing (Torchic > Blaziken, Sceptile barely looking like Treecko).
In Gen IV a lot of the consistency is gone. Aside from them both being penguins Piplup doesn't look much like Empoleon. And while Turtwig and Torterra are both green with shells the resemblance stops there.
Hell, even the transitional phases didn't tie the evos together well. Turtwig goes from Snapping Turtle to Stegosaurus to Ankylosaur/turtle/world tortoise hybrid without much color or design consistency between the three.
So I'm not terribly surprised.