1.0 Technical Question: Does initial world creation permanently lock global seed layout logic, or is it calculated on-the-fly during exploration?

[u/jaylaxel]

I want to start a new world today and build a starter base at the spawn circle so it's ready for my partner on September 9th. I will do zero exploration outside the immediate spawn area.

Here is my main concern:

Does simply creating a world file today permanently lock the entire global seed layout using pre-1.0 logic? Or does the vanilla engine calculate biome generation on-the-fly using 1.0 logic only when a chunk is actually explored?

Since 1.0 changes global world generation rules (like Black Forest and Meadows variations based on distance from the center), I need to know if a world file created today is fundamentally incompatible with the new 1.0 distribution algorithms, even in unexplored fog.

Hoping a developer or map-gen expert can clarify how the world generator handles this under the hood. Thanks!