I'm saying that Latin is Latin, as opposed to Latin was Latin.
Of course, no one can say "with absolute certainty that this is how the language
was used". However, I can say how the language is used -- or at least how it
was used when I used it and was among those who also used it.
The literature in Latin which has come down to us can be studied and we can
derive some rules based on those studies. Or we can study penguins, which
would probably be more interesting.
Having said this, I should also note that my post was a tongue-in-cheek
pose of indignation.