If my memory serves, there used to be a puzzle in the Watershapers Guild which used that item as a clue, but the puzzle was ultimately cut. I guess the flag identifying that book as a quest item wasn't un-flagged.
I had a suspicion that something along those lines was afoot But my mind kept niggling that it could be something really cool, either for its own quest, or something to do with Tekehu og the Shadow, which is under Nekataka.
I'll add this to the Wiki entry, and, ofc, suggest un-flagging it with the next patch or something, if possible.
And superthanks for the reply, now I can stop mind about that scroll <3