Well in all honesty and my experience it is going to likely depend on how the game generates the world. If it generates the entire map at once then no you would need to start over to get a new biome. If it generates as you explore then you would simply have to just explore a new area.
Most likely though if you try to play an old save over a map change you are looking for a buggy mess. Best place to really ask this question is the Discord. That is where modders and server owners are at. They have a better understanding of the game code and can really answer your questions.