I posted something similar around a week or 2 ago, according to the replies I received, existing maps will be updated in new biomes that haven't been explored on your map or other peoples map in your server, so if you haven't explored the Ashlands it should be updated but if you've discovered it then it won't be updated, again this is just what I've heard so take it with a grain of salt.
BUT with it being a EA I wouldn't take all advice for granted, you never know what new bugs you'll find after the major updates or what updates will occur after hearing advice on here or reading on the internet

We don't know 100%.
The developers indicated the plan is to incorporate future stuff into current maps but can't guarantee anything, and from the sounds of it anything already discovered (not under fog on the map) is set in stone so if you've explored mistlands, deep north, and so forth, you may have already screwed yourself.
The details weren't specific, and being in EA nothing is guaranteed, it's all part of playing in EA.