As far as Warner Bros and its movies go, the studio is presumably waiting to see how Wonder Woman 1984 performs on HBO Max.
Once those numbers come in, then the studio can decide which movies are worth keeping delayed and which ones should be put on HBO Max.
Throw in Paramount selling movies like The Trial of the Chicago 7, Without Remorse and Coming 2 America to streaming services like Netflix and Amazon Prime Video, and Hulu acquiring movies like Run and Happiest Season, and it just goes to show how significantly more important these platforms have become over the course of 2020, which is saying a lot considering how they’d already shaken up the entertainment sphere.