Well except I still call shenanigans on the theory. I would actually accept that this process
might occur before the age of one, right after the Argonian was born, but anything else beyond that age isn't that well supported, or at all.
The way I see it, each race in this universe have some juicy information reveal, whether from their race account it or from another account. Khajiit and the Dunmers are made from the Azura's wicked magic, Orcs are feces of Boethiah, I think it was the Nords that were cursed to live a very short life span at one point, Breton were love babies from Aldmers and some Nedic tribe, Dwemers try to become god and fail, the origin of the Mage Guild can be credited from the Altmer's influences, and so on. What I am pretty much saying is, if it were to be true, it should already be mention, accounted for, and in a way, common knowledge amount ingame scholars or joke accounts/story that one of the boss's employees of (insert occupation) changes six.
Argonians may be secretive, but how secretive depend on the individual and how much s/he kept their wisdom and knowledge in or not. In other words, just like everyone else.