I'm not that big af fan of Katherine Heigl. And I didn't like the way she shaded the show when she was still on it.
But I LOVE Izzie and I LOVE Izzie and Alex's relationship.
So I would actually really like for her to come back.
But if she only wants to do one episode or a few , I think they should just bring her back when the show ends so she and Alex can have a happy ending. Or just bring her in when Alex leaves the show.