If the default is off, most will have it off. If the default is on, most will have it on. All of which to say, no one cares, and google very likely knows that

If the default is off, most will have it off. If the default is on, most will have it on. All of which to say, no one cares, and google very likely knows that. Google will only care if enough of their users care. And they will probably operate in a fashion that keeps the maximum number of their users in the "don't care" camp. It's just business.