Evidence that the evidence used by some TBM's as evidence against the arguments used by some critics isn't true isn't evidence that the evidence used by some apologists to support their claims of Book of Mormon historicity aren't true.
Except that the discovery of a moon in Saturn's rings isn't evidence of the possibility that future discoveries in archeology (and what to disciplines could be more different than Archeology and astronomy?) might occur that are positive for the Book of Mormon.
Its nothing but an insinuation without any particularly strong logical link between the two phenomena based in preexisting assumptions and biases (Dude is already sure no such discoveries will ever occur, so the extrapolation, for him, needs no particular logical strength - just the appearance of it).
Of course, working backwards in this way, from the assumption that nothing of any import regarding the Book of Mormon will or can ever be found, to actually doing archaeological work turns shcolarly work on its head; working from theory and interpretation to discovery instead of from discovery to theory and interpretation.
This is what irrational polemicists with an agenda must do, however, to maintain a nice house on Hilton Head when they know that the very next storm may take the whole thing out to sea in little pieces.
The very next dig could begin casting serious doubt regarding the entire anti-Mormon edifice constructed around the Book of Mormon. Or, it could be the dig after that. Or, the one after that.
Or...