Ignoring the irrelevant (and misguided) remarks about what you think “the God hypothesis” entails, your distinction between necessary/unnecessary is what I was touching on a long time ago in this thread when I first asked whether lacking C2f would prevent interbreeding.
I’ve tried to explain this enough times that I’m not sure repeating myself would be helpful to you if you if the previous remarks were not. Nevertheless, I’ll try once more: If there were evidence that Adam had common descent, then there is evidence against the de novo creation of Adam, unless one stipulates that the de novo creation of Adam included an appearance of common descent. The broader significance here has to do with one’s epistemic attitude, so to speak, towards YEC. But it likely is of no interest to those who reject A and B.
(I realize that second to last sentence may be vague, but I can’t get too deep into it right now.)
I think many people, including scientists, are too quick to adopt a naive epistemology. How would you know you’re wrong about last Thursdayism being false?