Well the same thing was mentioned about Kos and game three showed that AlphaGo was very effective by both having few Ko threats and playing them when imperative. It also demonstrated effective gameplay as black with 4.4 & 4.3 opening.
Considering the large training data set, handicap games would certainly be included. It's a great way to test aggressiveness and the effectiveness to reduce the opponents' territory whilst building your own.
As an amateur, handicap games where you try to overcome 3 or 4 stones are some of the most educational experiences. It requires a lot more creative thinking and perseverance to come back from such a disadvantage.