As Microsoft prepares for the release of their next-gen console the Xbox One, they are continuing to try and make the transition for active Xbox Live holders on the 360 as seamless as possible.
Beginning August 27, all accounts linked to a Gold Family Pack will dissolve into individual accounts. For example, if you have 3 months left on your Gold Family Pack, each individual account will have 3 months as well, plus an additional 3 months that Microsoft is adding for the hassle.
This move is to make your Xbox One experience more organized. When you purchase an Xbox One and scan your Gold membership with Kinect, every account on that Xbox One will have gold membership. This is a great move from Microsoft.