I’m glad you found that, as it does sound as though Mises is saying the theorem is not just an explanation of how current money evolved. I’ll have to forward that to Wenzel and Kinsella who both admit to being of the position I described earlier.
However, it would appear than not only does the Ithcac HOUR disprove the theorem, but bitcoin itself does. You will likely claim that bitcoin hasn’t been around “long enough” to be considered a currency and claim it’s “just a fad” or a “bubble” or something, but that is irrelevant (not to mention whatever time frame you choose would be completely arbitrary). The question is whether the object “already possessed an objective exchange-value based on some other use at the moment when its use as money began”. This obviously wasn’t the case with either of these two examples. So it would seem that despite whatever other claims and qualifiers you might like to make—and I realize I’m probably committing some kind of sacrilege here—Mises has already been proven wrong in this case.