Not quite useless. The statement could prevent Google from later enforcing a patent against anyone who'd relied on that statement, via the doctrine of estoppel.

Not quite useless. The statement could prevent Google from later enforcing a patent against anyone who'd relied on that statement, via the doctrine of estoppel. And Google can't quite change their mind "at any moment" – more than one year after the first public offer/description of the technique, under US law, it won't be patentable. So by June 9, 2015, if they haven't patented it by then, they won't be able to. (It's likely already too late to patent in other jurisdictions, that don't have such a long public-description grace-period.)