Another name for this is “Excluded Middle” theories or reasoning, which say the question under consideration has a yes/no answer, or an either this/or that answer. The middle grounds of maybe or neither this nor that but something else are not even considered.
I think one has to be careful when saying that Dumbell reasoning applies to the real world of nature. There is considerable middle ground between complete free will and a robotic absence of free will.
There have been some interesting neuro-biology experiments on these issues, like evidence for a decision being made a short time before the subject is aware that the decision has been made.
The philosophical battle over free will has been going on for a long time. I think I will opt out for now, and wait for science to offer further guidance.