You're just trying to find faults in the PGE, even though there are none. It very clearly describes Cyrodiil as a jungle (which evokes a very clear image, not a general woodland), and is supported by Provinces of Tamriel (which was found as late as Morrowind). The writers of the PGE are Imperials living in Cyrodiil, so you can't exactly say that they don't know what a jungle looks like. The point is that Bethesda changed their lore, for one reason or another, not that everything about a Cyrodiilic jungle was somehow metaphor or exaggeration.
Lore should be interpreted, yes, but that doesn't mean that everything prior to the current game is wrong or that it is an entirely organic process lacking in real-life bureaucracy.
I was never regarded Cyrodiil as a jungle, just becouse Imperials wasn't looked like a jungle-origined civilization.
To me, this screams "boring and therefore wrong," or, more directly: "lets stick to comfortable clichés, guys." Just because someone lives in a jungle doesn't mean they have to look/feel Aztec. See: Amerindian inspired Ashlanders in Morrowind.