I think everyone's reading too much into debuts at the moment. A 30k-50k debut will be fine as long as as the album continues to sell (which, I think it will do)
It's great imo, a lot of artists sell way less and they get to release new albums.
20K is fine (I was kinda rooting for 30K tho )Ghost isn't even a top 40 hit yet. Either way, the album gets better w/ each listen. I was adamant to some of it at first (back in October), but now...