More generally, it's a good idea to follow news on developments not only of changes to privacy policies, but other corporate news as well. Companies get bought and sold, and these ownership changes may bring changes to the privacy policies or other data use issues.
Similarly, sometimes companies go out of business (I am NOT trying to start a rumor about Ancestry.com or any other genealogy company!), and what happens to the data might be different in a bankruptcy proceeding than the company's stated privacy or other policies may indicate.
In short, don't post or share any information--especially Personally Identifiable Information (PII) of living people--that you wouldn't want shared when privacy policies change or company ownership changes--especially if it goes out of business and bankruptcy proceedings put your personal information on the selling block.