Actually it probably is. Because anonymization gives the demographics info. Which is what big data cares about. Google doesn’t give a crap what illness YOU have. What they want to know is what a person of your race, gender, age, income bracket, and zip code has. So they can compare that to all the other folks in those demos, and get statistics to tell them group X is more likely to have illness Y.
Shortly after you will start see advertisements for treatments related to that condition.
So they are interested in your health condition as long as they can monetize it.