Isn't Abyssea Lilith's realm, i.e. the REAL Vana'diel? In which case everything was largely the same up until the battle of Xarc. (And it also explains how we are so much more powerful there and we see all the same NPCs and locales)
So what happened to the crags? And more importantly, what fucked up the world so bad in the first place? The Shadowlord was powerful, but Abyssea reminds me more of what Kefka did to the world in FF6, and I just don't think Raogrimm has that kind of power.
Well, that was actually caused by the 3 waring gods but still... you get the point. Something major came out of nowhere and just completely fucked up Vana'diel. I think SCARS, just going by the name, will be Dynamis v2.0 with us visiting the ruined cities. That's gonna be freaky though, having Maws in town lol (they can't possibly do it any other way, since in Bastok's case there was a mudslide and the path back to town forever lost)