This isn't something blizzard snuck it, its just someone who did a body mod draenei on showing an example of a different sized shape they could have if the choice was there.
I'm thinking really about this extending to all other races, we already have rotund pandaren and dwarves being portly, but often when I look at drawings of characters on sites like deviant art of how people would wish their character to look, its sometimes annoying to think how other mmos have given body modification and wow will never have that.