This change had already been experienced by the selected group of users given early access to its Graph Search facility.

BBC: Facebook news feed revamp learns lessons from mobile

To sell access to the social graph!

FORBES: Why Do Programmers Hate Internet Advertising So Much?

They want to make it clear this is not a web search engine but a Graph search with access to a set of people, places, photos, and other content.

FORBES: Mark Zuckerberg Unleashes Facebook Search To The World

Facebook said Graph Search is launching immediately in beta, although users will need to get on a waitlist to gain access.

CNN: Facebook introduces 'Graph Search'