As we agreed, rather than becoming involved with what could be a touchy moral argument and a question of religious ethics, you will not have the Companion take over the body of Nancy after the latter’s death. Instead, prior to Nancy’s death, while she is still ill, you will have the Companion ‘merge’ with Nancy and become part of her and the life she will lead with Cochrane.
Memo from NBC’s Stan Robertson to Gene Coon on the script for “Metamorphosis.” Quoted in Marc Cushman’s These Are The Voyages: TOS Season Two.
As I mentioned in my review of this episode, I’m not sure the ‘merging’ into Nancy’s body made anything less problematic.
I am really glad though that they cut the part where, “in previous drafts, when learning bout The Companion’s gender and her love of him, [Cochrane] had reacted far more dramatically…He flew into a rage, threw rocks and even attacked The Companion with a club.”