The last time it was in black was the W01 so I can only guess there is a reason they avoided it for the last 8 years. Maybe some new guy didn't get the memo. How they think black will stand out better on a dark car than white outlined with black is beyond me.
I've always thought to be honest, if I was Petronas, I would be disappointed with the exposure on the sidepods. I've just been looking through all the Merc cars and confirmed my feelings that it just doesn't look good just plonked on the side the way it is. Like this years car and last year it would look better without it on there and just the lines, which isn't the idea i would assume.