It is quite possible that Disney admissions might skirt by on the not selling the block out day tickets on the excuse that July 17th is a "Special Event" day. They are working the Cast Member admission block out (no Main Gate passes and no Cast Member ID admissions allowed on the 17th, but we can use the Team Disney complimentary admission passes to get in) in order to limit the amount of Cast Members going to the park. As GD had mentioned, "Subject to change without notice" will be the mantra of that day.
