Is deepmind moving back to (py)torch?

Hi, I am working on natural language entailments tasks with keras but despite some searching around I couldn't find any convincing example of an seq2seq with attention model in Keras (or a neural cache model for that matter) On the other hand I just looked at pytorch for a couple of hours and dynamic/control flow operations seems really easy to code in pytorch . Is everyone progressively moving to pytorch while only using tensorflow as a backend for keras ? Is the pytorch movement even spreading inside google ?