If you read the paper linked above, rather than the wikipedia article, it becomes pretty clear that they are very explicitly talking about free will and that th

If you read the paper linked above, rather than the wikipedia article, it becomes pretty clear that they are very explicitly talking about free will and that the result of the theorem is directly related to the quantum mechanical science behind the thought experiment. So saying 'there's no scientifically good reason for it' is off the mark. It's also not specifically saying there is free will, it's only saying, if an experimenter has free will in deciding how to do an experiment, then the subatomic particles have the exact same kind of free will in the result that is shown from the measurement. If by some other method we conclude that an experimenter does not actually have this 'free will' thing, then the theorem doesn't really say anything about that. But the whole point of the theorem is directly related to the concept of free will, and naming it the Free Will Theorem is perfectly accurate.