I have one memoir out in the world about my time living and teaching in New Zealand and I changed all the names out of respect for my neighbors, peers, and colleagues. I have also written extensively about healing from my divorce on Medium and never used my Ex's name. I'm in the process of writing a second book from my late dog's point of view and changed my Ex's name from the very beginning. Sometimes I start referring to herin my head as the changed name! A true sign I have moved on. No matter what, people close to us will know who we are writing about but we can't change that. I like your idea that if doesn't add to the story then why use real names.