My point is that the proposal that the default should always be to leave things the way they are (which is the whole point of the Chesterton’s fence principle)

My point is that the proposal that the default should always be to leave things the way they are (which is the whole point of the Chesterton’s fence principle) is not a good general principle, because if you currently have very little understanding of the situation, “the way things currently are” could just as easily be extremely dangerous.