*Spoilers ahead*


So when I had finished the Dawnguard questline on the Dawnguard side, one of the first things I did was to return the Elder Scrolls to the Moth Priest. However, he didn't take the Dragon scroll, which seems kind of odd. There appears to be no way to re-sell it the Winterhold library either.

Does that imply that the Dragon scroll could be a part of a future DLC?

I don't know I've got 3 of them at the moment so maybe in the new DLC the Dovakiin starts an Elder Scroll library or has to fight off a legion of angry moth priests.

The Wikia says you can sell it to the Orc in Winterhold. But don't you need it for the main quest? They might have prevented us to sell it if we haven't done the main quest.

Most likely you can only sell it to Urag if you have not already sold it and brought it back. As a vampire who had previously finished the main quest, my character Braggen is stuck with all three. That would not have anything to do with hints for future DLC though. Some can get rid of all three scrolls.

Oh well, that makes sense

He didn't take the Dragon Scroll because you use it in the main quest...

^, the next DLC is called Hearthfire btw.