Mary Norris defends her position declaring that in her book, "than" works as a preposition." (And, in case you don't watch the video, she does understand the argument that "than" is a conjunction)
I bought the book, "Between You and Me: Confessions of a Comma Queen." The passage on page 72 — which she isn't going to change — is:
Nothing makes it clearer how intimately and deeply pronouns are embedded in our lives than having to alter them to refer to someone you’ve known all your life. Just when I was mounting an assault on the Italian language, sorting the nouns that ended in a (mostly feminine) from the nouns that ended in o (mostly masculine), struggling to make sense of the ones that ended in e, the difference between sex and gender leaped out of the textbook and into my real life: my younger brother announced that he was transgender. Dee was two years younger than me, and we had been close— or at least I thought we were close. We grew up together in Cleveland and we both escaped to New York, where we were friends, sometimes neighbors, often confidantes, collaborators, drinking buddies....
