Are the descriptions of Valenwood and Black Marsh provided in A Dance in Fire and The Argonian Account accurate, or are they exaggerated or even fabricated for the sake of entertainment? If Bethesda, hypothetically, decided to make TES VI in Valenwood, would they have to go by what they have described in ADiF, or could they just ignore it?

I think they should stick to it however they could pull a cyrodill on us.