I think current offers expire May 2nd. If you didn’t test in the Fall, there is still an opportunity for Spring testing. For those Spring testing, they can only get onto waitlists. My guess is that they take that time between May 2nd and May 19 to allow for Sprint testing and to re-sort waitlists (if applicable).
Elementary waitlist offers go out 10am starting May 19th. That is also when families can add a school if they didn’t previously add one.