^^^
Well, you could try to change the story arcs a bit. For instance, what about the Earth Alliance as "agents of chaos" for the Shadows? Instead of turning isolationist, the EA becames increasingly militarist and expansionist. Or mybe the Vorlons and Shadows have a different history or a slightly different motivation.
Just some random examples which come to my mind...
Unless you do a complete overhaul of the story (to the point where it's not really the same story anymore), it wouldn't work. Writers are just not going to want to spend that many years of their lives retelling what is essentially someone else's story, but with some new twists thrown in. (And there's no chance of JMS himself redoing it, based on his public statements on this over the years.) And viewers are just not going to be as into a heavily arc driven show which is a retelling of a story that's already known (and that's already been told in the exact same medium), as they would be for something original.
Again, this is a very different situation from BSG. BSG78 had the iconic characters and the premise of "Cylons destroy the colonies and Galactica leads a fleet of survivors away to freedom". That is basically all there was to it. There wasn't really an overarching story arc to the show beyond that sentence, and that's really all that Moore reused. The story arc of nBSG was completely new, once you get past the miniseries. Do you think BSG would have been nearly as popular if everyone pretty much already knew how the story was going to play out from the beginning, before we started watching, and we basically already knew the answers to the mysteries?