Yes, it’s BI, but one research firm has found that overall search volume experienced a meanginful year-over-year decline last month for the first time in the six years it’s been tracking such statistics.
You likely won’t see Google comment on this unless to refute it or misdirect with an alternative stat. It’s also not a foregone conclusion that apps, largely powered by social media, are indeed the cause. But they’re certainly one of, if not the, most likely candidates. It would certainly help explain Google’s mad dash with things like Google+ and Google+ Local.