I already run a RYT 200-hour through Yoga Alliance: Do I need to change anything about my program?

Nope! You can keep your training exactly as it is, however you will need to generate Core Competencies when submitting your program application. In short, you can keep your training content exactly the same, but instead of explaining how many hours are devoted to each category of the training, the focus is more on student learning objectives: what skills, tools and knowledge do you expect your students to have at the end of your YTT?