"You were raised in a castle as a creature of wealth, power, and privilege—none of it earned. Your family are minor aristocrats who saw to it that you received a first-class education, some of which you appreciated and some of which you resented. (Was it truly necessary to read all those ancient histories in their original Draconic?) Your time in the castle, especially the many hours you spent observing your family at court, also taught you a great deal about leadership."
No, the writer is saying that history books are written in Draconic, not that this noble learned anything about arcana.
I mean, I do believe there would be dragons who would love to watch History Channel and yell about all the things they get wrong, because they were there, but I think the suggestion that Draconic is the language of history books is pretty goofy.