Conveniently, some parties like mostly Google but also Facebook and Twitter have both a big presence in the tracker space and also a site users often visit directly. Their information is going to get much more valuable.
Do Google ad tracking cookies actually live on the google.com domain? Seems like an ethical violation of some kind if so.
None of these changes really affect Google, since users typically use their services every day. It's almost like Apple is helping Google get more powerful. It's the smaller ad networks and exchanges that will suffer a lot.