Could you please read the first topic in dev. Section that explained why terrains were removed? Terrains and shaders aren't compatible or they are too much for the engine to run.
There's also a handful of things that terrain did such as complicate the code, making hard to bring updates, limited bricks, meaning they loaded slower than now (bricks are 90% faster) and a couple of other things.
Who doesn't want a fully customizable day cycle and the ability to change the texture of the ground without having to make a pack and a new map each time you just want a different texture for the ground.
