Nothing like completely unsupported speculation to make you look like an ass.
Interesting, but I'm calling false on this one. Call me naive, but Google is almost 16 times bigger than Blizzard Entertainment and aren't even close to raising the same level of public awareness. Also, if diversity would be an issue, it would normally start with low-level employees rather than at the top of the tree where the people work who are actually making hiring-or-firing decisions.
On top of that, out of everyone they could let go, letting the one go who started it up and is now the face of the community (Ben Brode) just because he's white seems way, way far fetched.
Far more likely is that, working for the same company for 20+ years, in a creatively demanding environment, is the reason why you would move on. It baffles me that this kind of racism even seems viable in your obviously well educated mind.
It seems you're focussed on racial issues. Even though you might have the best intentions, this perpetuation is the reason why racial discussion even exists.