There is a famous player called Takemiya Masaki. His style of game is called Cosmic Go, and his games were some of the most beautiful games in history. He had an amazing ability of making this natural flows and building massive central territory: something against conventional theory.

His style died eventually because no-one could play like he did. Some professionals even mentioned that such a style could not be played unless Takemiya Masaki had amazing reading skills.

Alpha Go has amazing reading skills. So he can actually easily afford to play such a style. Its like the revamping of a theory we all know its playable but as humans have a hard time having a winning rate with.

On the other hand, alphago is definitely playing moves that are plain bad for conventional theory, but manages to get good positions regardless. Its possible that alphago is just more thorough, and human pattern matching naturally discard moves that most of the time are bad.