The solicits have to be submitted at an early point in the script's life so it's entirely possibly that in later drafts, Dini and Burnett got an idea to make it more of a Ventriloquist-centric story. Maybe they even realized 'we can't do another 'Harley & Ivy vs Joker' story.Finally, I wonder why this was teased as a Harley and Ivy story when it clearly is more of Ventriloquist one.