New zones/biomes are always added to your world, they're just added in the unexplored areas. You'll be fine. Character progression isn't tied to your world, it's in a separate 'save' file, this is why you can move things between worlds for convenience. Additionally, none of the updates have wiped any world, it's not something you have to worry about. Unless you play on a dedicated server that isn't under your control, the owner could wipe it if they want.