erm...the info is from the official guide...
Those have been known to be quite wrong from time to time.
EDIT: Now that I think about it some more, you should go do some more of the MQ and return there *before* the meeting between Tullius/Ulfric and the Greybeards. Delphine and Esbern will have furnished the place a bit more, but you'll want to get there in order to loot stuff before it all becomes marked as owned property.
Those books may be there on your later trip.