Well, Gail's always pretty careful and diplomatic when she talks about this stuff, mostly just "they wanted to take the title in a different direction than me" sort of thing, but the gist I got from her comments, which now of course I have no idea where I read, was that she wanted to do quirky ludicrous chaos and they wanted to see sober boilerplate hero and maybe some angsty horror. Hence, Gail left the title and Remender came on and the quirky ludicrous chaos turned into sober boilerplate hero with some angsty horror (I'm extrapolating the editorial desire for angsty horror from its presence there, but I'm reasonably sure about the sober boilerplate business).