Originally posted by Gladi8er65:

It is that way to try to prevent "forced-wipes" when the new biomes are introduced. As mentioned those empty biomes are place holders awaiting updates.

That being said, areas that are EXPLORED (even the empty, unpopulated biomes), will not populate correctly when the biomes are added / updated.... only unexplored areas of the map, hidden by fog-of-war, will successfully update.

Where have you heard that from? Cause as far as I'm aware an empty unpopulated biome has never been introduced yet and therefore the consequences of how they will be affected when the biome is introduced is untested and unknown. The "explored" rule we know for introducing new poi's might be different from a whole biome implementation.