This update could be a consequence of Hummingbird, or a lining up of Google's recent changes to search functioning with a change to its ranking scheme. With Hummingbird, Google appears to be transitioning from a PC dominant understanding of 'exact search' to a mobile device based concept of exact search.
If G is switching to weighing full queries or statements (that mobile users like) as being more 'exact' than the generic short or long tail keywords we are familiar with, it means the ground has shifted from under us all in IM. As summarized by an article at Venture Beat: "While the Google of a decade ago was focused on delivering search results based solely on queries, the Google of today is drawing insights from a variety of other signals — location, social connections, and even your previous searches...Stuffing your webpages with SEO-friendly keywords isn't going to cut it anymore. Or, as Google search guru Matt Cutts likes to put it, the Google of the future ‘is about things, not strings.'"