The Flash has been going through a lot of behind-the-scenes shakeups, but it’s a movie that would benefit from being released sooner rather than later following Justice League.
Personally, I suspect that The Flash and Suicide Squad 2 will drop on those dates.
As for the other 2020 date, well, there are plenty of options on the table.
As Suicide Squad 2, despite its negative reviews, Suicide Squad raked in a lot of money for Warner Bros, and since Jaume Collet-Serra is reportedly the frontrunner to direct, releasing a sequel in 2020 would be a wise move.