Wrong type of generation in a biome

So I wanted to see everything in the new pre release but later I got to see that the mountains were not that high like at level 71 and the same height as the nearby plain. I am pretty sure this is not how it is supposed to generate if it is well that's weird but I don't think it is. This is especially wrong if cliffs are being updated.

Seed: 1504574827144859421