Was This Graphical Update Necessary?

[Evergrey]

New sculpts don't have to look different, though. My character's mouth looks mostly the same. Other's have entirely different lip shapes, and differently shaped lipstick too.

I can't say anything about why the colors are different.
But just like how each face have a different shape. Why else have multiple faces to choose from, right.
So if one face already have a base shape that works more with the update less had to be altered.
Where other faces might've not been so lucky with how they were originally shaped.

My theory at least.