The description of the Trojan Reach as unknown territory after 700 years of contact and trade with the Aslans on the other side of it, OTOH, is much too big a stretch. The Trojan Reach in Leviathan fits a lot better with Year 400 than with Year 1100.Recalling how trackless parts of the Trojan Reach are described in the 1100s, the idea that Imperial records might be incorrect with regards to the states of The Beyond is not a big stretch.
Lots of inaccuracies and misunderstandings, sure. Near-total information failure, no.
Hans