Alternate block models for blocks such as grass and stone do not work as intended

In previous versions blocks like grass and stone (blocks which use alternative block models) used the normal block model, rotating it 90, 180 and 270 degrees in order to create a completely random arrange of textures (see

).
However in 17w48a the default resource pack uses only the normal model and a 180-degree rotated one, creating a specific pattern (can be seen in the circled areas of

).
The same goes for any block that uses this method:

{
    "variants": {
        "normal": { "model": "name_of_defaul_block_model" }
    }
}

(See

)