well without really knowing... Try this mental exercise ...

the TOTAL world size hasnt probably changed from first EA release,

So the RNG is populating the same size physical world

But they have added more content inside each of the the biomes.

So theoretically the RNG for (Total number of "objects" spawning} across the entire World is the same. but spread differently inside biomes... (well more game inter-active biomes)

well if my theory is right its then LESS "objects" per biome

Additionally the manner, type AND location of those "objects" may have changed...