These changes do not break any existing functionality, Field Expansion is an addition to the API. Field Expansion is basically support for very simple joins.

Batch Request support has existed for some time and allowed similar result sets to be retrieved. Batch Requests are significantly more complex to construct and are not well supported by tools like Facebook's Developer Open Graph Explorer.

It's fairly standard practice to provide a list of backwards incompatible changes (along with instructions on how to mend your code) when making changes to an API or a framework.

Maybe these updates to the FB Graph API don't break anything? Would be good to hear from someone at FB about this.

It doesn't affect it in any way: http://facebook.stackoverflow.com/a/12203207/214773