With a start date of august but beginning with DO in June, with June or JULY movement, could be a yes or a no. I know of two people who had waitlist movement for MD after matriculation to DO. One was able to go because it was only 1-2 weeks in and no exams/quizes were held yet. The other was 3-4 weeks in when we'd already had a quiz and exam. The offering school rescinded once they learned the student had already begun taking exams. I will say though that there may have been a misinterpretation or miscommunication here, and I cannot verify that.
Basically just examples if how it may or may not work. I agree with the above that it will be school specific based on their policy.