One thing that isn't made clear in this writeup is that Master plays in a very nonhuman style, as opposed to the version of AlphaGo that beat Lee Sedol, which mostly played like a strong human except for a few surprising moves. My first guess when I saw Master's games was that it was a program like AlphaGo that had its policy network trained from scratch rather than being bootstrapped by being given the goal of imita…
Since AlphaGo's original training was to predict human moves, it should know how surprising a move is in addition to knowing how strong it is. My thought at the time was it could improve its game against humans by giving surprise value some weight -- when it can pick a slightly weaker but highly surprising move, pick the surprise.
I like your idea of maximising the 'alienness' of play though probably not to the exclusion of playing the strongest moves.