Apparently nobody in this thread bothered to actually read the article? The UFC is not adopting "official" rankings, the thread title is misleading. All the article says is that Fight Metric will be conducting polls with members of the media to provide fighter rankings that are up-to-date after every event, but these are not official rankings in the sense that the UFC will not be using them to decide matchups and title shots. They are simply rankings based on the opinions of various members of the media.
The term "official rankings" isn't even in the article...