Originally posted by CritMasterFlex:

Originally posted by Weaver:

We have seen a lot of questions regarding whether or not you'll have to create a new world to get the Hearth & Home-content, and the answer is that it depends

While it's fair to say that there hasn't been a definitive answer for the question OP asked, this is also not an answer to that question. H&H will not add any new regions.

any one biome you go into that is not finished will not be upgraded when that biome comes out.

Is the answer from the devs. For example, you go into a mistlands zone and it will not update that zone on your world. Thus, stay out if you want it to update. This also goes for Deep North, and Ashlands.