I really love this game so far. Halo 5 is pretty incredible. Everything I would want out of a next gen halo game. The only thing I am wondering is, 343 said progress made would be carried over. I really hope this means my kd as well. It’s part of the progress I made and I would love to have all those kills, and deaths brought in to the final game. Without them I would feel as if the other kd wouldnt be my true kd. So I really hope 343 does allow the kd to be brought over. Even if people dislike there old kd, they could put in an option to start a new or bring your old progress. Im keepin my fingers crossed! 
I don’t see why they should keep the KD. I mean it was just a beta. It wouldn’t really be accurate, either, since when the game comes out your previous KD won’t be accurate to the updated version of the game.
I wouldn’t worry about it that much. You played the beta, which means you are already going to have a leg up on everyone else who buys the game latter in the year=pure ownage for the first few weeks 