It's not like your game is going to become canon history for the setting...
... well, maybe it might. But, that's besides the point.
I don't know how many times I've played FR, made some great adventures using the campaign setting where characters had significant influence on the future of the lands, only to have WotC come out with a new edition putting the history of the world a little further and... dang it!... our characters are not in it!
Anyway, the point is, I think Audalis is offered up as a setting for you to take and run with. And your Audalis will probably look different than Olan's, or Alacrity's, or Almerin's, or mine... great! As far as I know, I'm the only one who has built an entire mini section around Rayther (called Shinara's Keg), which has: lots of mountain ranges surrounding it, a younger khordish expansionist clan, loads of khordish and orc ruins, and is currently being scouted out by a Orc worshipper of Tyrannis as the staging grounds for a complete take over of northwestern Antaron (and then the 5 kingdoms).
Orc ruling Bayris? Probably not in Olan's Audalis. But a definite possibility in mine.
Heck! Almerin added a new god in his Local Legends game (which we subsequently killed... but still...).
I'd say you have freedom! We might even steal some of your ideas and run them in our game!
Ayrn