Why not?
After last chapter we learned that you need to kill DR outta the victim, so that they can be free of it.
As much as I don't like the idea of DR Loki, it seems possible because it increases tension - the holy bums don't seem too impressive for now.
Also, Luffy promised to stop Loki (read: beat some sense into him) if freeing him makes Loki rampage.
But at the same time, Luffy is unlikely to kill, unlike Zoro, plus Loki is a huge ass dragon, and I can see Luffy being on yet another "gotta recover" phase while Zoro can safely kill DR Loki and get him back to normal.
Other than that I legit don't see any worthy opponent for Zoro on the island unless more holy bums arrive or Imunko proves to be more troublesome than we think.