I don't see where 10ya comes from, but DMY, MDY, and YMD, at least, are all plausible interpretations.
> when I searched on the problem just now, I found complaints about the same problem going back to 2006.
During the first decade of the 21st Century, I regularly encountered dates, especially handwritten, with single digit years, because some people first reduce to a two-digit year when writing dates, but then -- as with any other number -- leave off leading zeros.
But even ignoring that, I've never ever seen a single person write a single-digit year. Not alone ("I graduated in 1" vs "I graduated in 2001"), not in dates ("August 7, 1" vs "August 7, 2001"), not anywhere.