I don't see the point of being confident about this in either direction. I will not assert for certain but (or, IF) they had dice for 12000 years (12,000!) and to be so certain they didn't know anything at all on an intuitive level is a bit strong a position to take, I don't see that as a safe null/default hypothesis.

I had also said "..., THEN it's not implausible" so I don't love how you quoted a strawman in the first place.