To have free will, the actions of a SAO cannot be completely predictable. To be free of complete predictability, at least some of the SAO's actions must ultimately depend on some kind of random event. At the most fundamental level, this must be quantum indeterminacy.
This is not what most people mean by "free will". If I ask you to pick one of two cards, and you are initially reaching for the left card but then a random quantum event causes a muscle spasm in your arm which makes you to point to the right card instead, would you say this was an example of free will on your part?