The last time Cormier tried to make 205 he suffered kidney failiure, hes a great fighter but I just dont light-heavyweight being his future.
He has been talking about it in recent interviews.
If Velasquez beats JDS in their rematch and Cormier still insists that he won't fight his teammate then there really isn't much reason for him to stay at heavyweight.
I'm aware of his past weight cutting issues, but those were brought on by attempting to cut far too much water; there is no reason why with proper supervision he couldn't cut a relatively small amount of body fat requiring him to cut very little water weight to make 205.