Stephen Hawking has died at the age of 76.

[RoadRunner79]

That sounds like a textbook example of the argument from ignorance.

You don't actually understand the argument from ignorance do you?

"Not a shred of evidence... therefore improbable" is not the argument from ignorance. That is being reasonable.

"Not a shred of evidence... therefore impossible" is the argument from ignorance.

No one said it was impossible or that absence of evidence was evidence of absence, we're just saying that making up some magical shit out of thin air and expecting it to still be probable without any evidence is about as irrational as it gets.

Argument from Ignorance  Description: The assumption of a conclusion or fact based primarily on lack of evidence to the contrary.  Usually best described by, “absence of evidence is not evidence of absence.”

Now I don't think that your inclusion of "probably" really makes all that much difference.  It still seems like the conclusion is assumed, until there is evidence otherwise, which would be the argument from ignorance.  There wasn't any evidence or reason given to the claim, but was stated, that it wasn't proven otherwise.   What is it that you think that I am not understanding here?