This would be an amazing resource. From what little we've been told by WOTC, the upcoming FR books will talk about a few regions in detail, and largely ignore the rest. I've bought most of the old editions, and trying to synthesize my notes and highlights has been an incredible pain.
This is really incredible work, and is the first thing I've seen truly worthy of the Dragon Queen. Mad respect for the amount of work that must've have gone into creating this.