DjinnFor said:
A development studio losing key creative/design directors just before release is like the Chief Development Officer of a major company resigning a month before the company launches a new product line.
You really need to learn how game dev works. At this stage of development, content lockdown, they're essentially in skeleton crew mode - polish and bug fixing. Art direction is set, and chances are any assistant art directors or various team leads can step in for art related decisions, since they have the rest of the game to match up. Compared with the beginning of dev when the art style has not been set yet.
Depending on the studio structure, a director of product development is probably a studio wide position where they oversee things like which projects get the go ahead and funding, or product tie ins with retailer exclusives or distribution licenses on Steam, etc. Or maybe sets code policies and oversees how the studio grows in terms of development for future titles, shuffling people around various projects as they roll off, hiring policies, licensing other products, etc.
But he doesn't have much of an impact on the actual development, and hardly a key figure.
I.e. they're probably not satisfied with the result and want to distance themselves from it and get a new job before the shit hits the fan and the game (& their reputation) tanks. That, or they don't like their job... which could be indicative of studio-wide employee dissatisfaction.
Or like I said before, with things in lockdown and less workload, they saw an opportunity to move on to other positions (An art director on 3 Bioshock titles might get bored after awhile).
And they probably have internal people like assistants who can step in and help fill the hole in the meantime.
