What is happening is a consolidation of privacy policies across most of the services Google offers. Other companies and services do this already rather than maintain separate documents, agreements, and records across several related sites. This way there is a single privacy policy that applies across Google products. That is a good thing: it’s simpler for users to understand, they don’t have to sign multiple documents, they know that certain things are and aren’t private across multiple services, and now something like removing demographic data from yourself applies universally, not just on one service. Why shouldn’t it be that way?