Originally posted by Łαяsι σð:

Here's from the FAQ of their official discord:
Will new content be added to my world I currently are playing on?
New content such as tar pits, mountain caves and Mistlands in the future will not appear in areas that have been already generated. Areas are generated 300-500 meters from a player's location. Exploremap and resetmap has no effect.

Ah well there we go, well then hush my mouth apparently mistlands is confirmed to work the same. Well that's gonna be interesting, I'll have a time capsule world of spider forests and dead plains lol