The published research indicates the deposits adhered to the coin are consistent with ancient burial and not consistent with the artificial aging techniques employed in Transylvania in the 1700s when the coins were found.
I'm happy to accept their hypothesis that they're actually ancient and barbarous. I'm not happy to accept the concocted story about an "emperor Sponsian" who briefly ruled in
Dacia. The coins were purportedly found in a single
hoard in the 1700s in Transylvania along with a bunch of
fake Gordian III gold coins, all clearly made the same way (casting) by the same artist. So why would we credit any authenticity to the products of a known counterfeiter?
If we accept that somebody named "Sponsian" did exist in Third Century
Dacia and put
his name on these coins, it could have been anybody - the goldsmith, one of the goldsmith's friends, or a wealthy landowner wanting a few pieces of gold with
his name and
face on it. If they want the "Emperor Sponsian" theory to be accepted, they're going to have to find some more coins, or some other archaeologically credible evidence of
his existence. They didn't believe in Emperor
Domitian II, until they found the second coin; Emperor Sponsian requires the same level of evidence.
If, as the academics in that article presume, there was a large and viable economy actually using these coins as
money, then we should have found more than one
hoard of them by now. It's not as though nobody in
Romania has a metal detector.