The theatrical release landscape is changing, and Warner Bros. is really pushing for HBO Max subscriptions. Offering so many new movies is quite the incentive. The Suicide Squad will be released August 6, 2021.
A similar release is already planned for Wonder Woman 1984, which will come out in theaters and on HBO Max on December 25, 2020.
IGN reports (emphasis added):
Warner Bros. announced an industry-shaking approach to distributing its films in 2021, revealing that it will be making all 17 of its theatrically-released movies that year available concurrently for a one-month exclusive window on HBO Max. That means United States-based consumers will be able to watch highly anticipated releases including Dune, The Matrix 4, The Suicide Squad, Mortal Kombat, and more at the same time on HBO Max as they would be able to see them released in theaters. More importantly, watching the movies will require no extra cost to HBO Max subscribers.