And he takes what was always kind of a running throwaway line and actually makes something out of it. Much like what he did with the Skrull cows, which I loved.
A lot of people think Alan Moore over at DC was all about the darkening and throwing away everything before. No, and certainly Byrne wasn't here either, and they were in fact doing the same thing. It's just that what Byrne does is so obviously within the FF universe. But they actually were part of a similar movement, along with Miller, in that they were developing what they were working with, which often had been allowed to get to a certain stage and then stopped for a long time.(DD would be an excellent example of that) Nothing either creator did with pre-existing characters wasn't already implicate in their history.
(Except KILLING JOKE, an exception that proves the rule)