Interesting. I wonder who else is capable of making a bot of this complexity? Like the article said, it's probably not Google. They already have AlphaGo and wouldn't try to hide it under a new account.
Maybe this is a message to Google and other people training up AI programs using Go that another player is in the AI game.
Google published a pretty detailed research article about their approach a year ago. [1] A competent deep-learning team with access to a compute farm of ~1000 gpu's could be be following the google recipe. That is a nontrivial expense though, e.g. not some college kid in their dorm room.
I'm surprised nobody has mentioned the lowercase 'e' in the "Master" logo. Seems like a dead giveaway.