Instagram has updated it policies to reflect that it now shares your data with its parent company Facebook. This most likely has no affect on most users and Facebook already has all the data anyway.
The major change here is that the old policy stated that instagram shared your data with "Service providers" and third party advertisers, and now it shares that data with "Affiliates".
None of this should come as a surprise though as Facebook is after all a company that earns its paycheck by collecting user data. Users are still able to choose who their instagram photos are shared with, and they still can choose not to post the photos on Facebook.
The new policy states: "We may share User Content and your information (including but not limited to, information from cookies, log files, device identifiers, location data, and usage data) with businesses that are legally part of the same group of companies that Instagram is part of, or that become part of that group ("Affiliates"). Affiliates may use this information to help provide, understand, and improve the Service (including by providing analytics) and Affiliates' own services (including by providing you with better and more relevant experiences). But these Affiliates will honor the choices you make about who can see your photos."