The home distribution rights for Across the Spider-Verse are in a rather interesting place. In April 2021, it was reported that Sony Studios had signed a multiyear deal with both Netflix and Disney for shared streaming rights to Sony films coming out between 2022 and 2026. This deal includes Across the Spider-Verse as well as the third film in the series, Beyond the Spider-Verse, due out in March 2024.
As for releases like Across the Spider-Verse, the film will be available on Netflix with "first-pay-window-rights" for the first 18 months of its home media release. While it will not be streaming concurrently with its theatrical release, it will be available on Netflix following its theatrical run.
Following its 18 months on Netflix, the film will likely be moved to Hulu to join several other Spider-Man films with a "pay 2 window," meaning that viewers will have to pay some extra fee on top of their Hulu subscription.
For anyone else looking to watch the film as soon as possible, Spider-Man: Across the Spider-Verse will release in theaters on June 2.