While Disney has not confirmed The Princess Diaries 3, it was a script at one point. "It's a script for the third film" It's a script, "Anne revealed on Watch What Happens Live in 2019. Details of the plot of the script have been kept hidden.When we told him that in Meg Cabot's 16th book in the series, The Princess Diaries, Volume XI: Royal Wedding, Michael and Mia get together, get married and even have a baby, he seriously considered what it would mean for his character . "I do not know how I feel about it," he admitted.