And now I can confirm that it works. Killed korrak earlier, got completed status, could turn it in. Note that it did not require me to loot the head of korrak, but I saw some other people looting it. I was confused at first but I guess that is the other version of this quest.
Im still having issues with this. I can see the questrewards but cant select any of them. I handed the Korrak quest in while it was swapped, so I cant abandon it (since its already "done"). When I click on an item (Bloodseeker) and click "Complete quest" it just "un-selects" it.