Split brain experiments show that a person rationalizes and accommodates their own behavior even when "they" didn't choose to perform an action[1]. I wonder if ML-based implants which extrapolate behavior from CNS signals may actually drive behavior that a person wouldn't intrinsically choose, yet the person accommodates that behavior as coming from their own free will.
[1]: "The interpreter" https://en.wikipedia.org/wiki/Left-brain_interpreter