Draconian or Destroyer 666 would make me very happy. Demons and Wizards seems unlikely but would be awesome if Andy could pull that off.
Dying Fetus is definitely a possibility as well but that might be one to many brutal death bands among the first 20 announcements (With Suffocation and Nile already announced).
Doro could be possible as well....especially if Amon Amarth is going to be sailing with us in 2017 (considering all the teasing at the beginning of announcement time with the 'A' bands and Nordic 'A' bands and the comment that we will be coming back to 'A' a little bit later). As much as some people shit all over "A Dream That Cannot Be" I think it is a really good song and would love to see it performed live.
Glad I wasn't on in 2015 as the repeats would be starting to annoy me a bit
If we're brining any more 2015 repeats make sure they are Arch Enemy, Trollfest or Alestorm