From "Recurrent Neural Networks" patent. This doesn't sound narrowly constrained to me. This just sounds like a RNN, which according to wikipedia, were conceived in 1982.
Read the applications for yourself. I'm not a patent lawyer but they seem to be unbelievably broad.
I think people pointing out that Google defensively files patents may be correct and I hope that's the intention with DeepMind's work, too. I am a fan of the audio work they did with WaveNet since day 1 and was so happy the paper was out for all of us to read. Still, I was hoping I may be able to (read: "daydreaming that I might be capable to") build on it, some day.
Organizations change leadership and they switch focus, too. I believe patents slow-down (even stop) progress and they are quite hypocritical, overall (show me a patented invention that was so unique, the author/owner didn't "stand on the shoulders of" 100's of years of freely available science to derive/discover/invent it and... I will agree for that specific case).
As a deep-pocket company, Google can afford to file patents and has a track record of being responsible about them in the community. It makes about as much sense to be mad at DeepMind for not filing them.