Don't get tripped up by etymology! It's of questionable value to semantics.

There have been arguments for free will that depended on the supernatural and I think that's what the critics here are focusing on. To contradict myself, the origins of the term are with the Catholic Church and intended to justify very specific supernatural positions.

But it's not an inherent aspect of the claim, philosophically. Nerds have been arguing about this for millennia and have enumerated a very long list of framings that make their position (pro or con sliced ten different ways) possible (the lowest of philosophical claims). This includes, but is not limited to, hardline atheistic materialists like Daniel Dennett, a compatibilist.