I think Free Will must be understood from the point of an actor who is trying to influence other actors. How will the actor we are trying to influence react? WE cannot force their reaction. Therefore from our point of view they have free will. We cannot control their will. Whereas, if they were puppets we could control their behavior to a large degree.
This has to do with the point about agency in the article. Everything in your "light-cone" can and will affect what decisions you make. But there are so many butterflies in your light-cone that you cannot say any one of them (alone) decides what your decision is. They cannot force your decisions and thus you have free will. No other actor can control your decisions. You are free of their will, thus your will is free of their will. Thus you have "free will".
This has to do with the point about agency in the article. Everything in your "light-cone" can and will affect what decisions you make. But there are so many butterflies in your light-cone that you cannot say any one of them (alone) decides what your decision is. They cannot force your decisions and thus you have free will. No other actor can control your decisions. You are free of their will, thus your will is free of their will. Thus you have "free will".