I was trying out the new features in a newly generated world, and I found this plains biome with oddly colored grass. Well, so I thought! But it turns out it's a Swampland with almost NO trees, except in the water... quite strange. I'm pretty sure this is a legit bug and not just some strange little thing I found in my world, because the whole biome was like this. Pictures are included.

P.S. in case you were wondering why some chunks weren't loaded, I had render distance set to 8, so that's definitely not a bug.