I mean, there's a fairly obvious method to putting four Harley Quinn films into development; They wanted another Harley Quinn film. There's no concrete information that all four Harley Quinn projects will be made. They seem to have employed a sort of writer's room approach and sought multiple scripts for projects, which is the way WB has worked in the past. This is the one that has excited the studio, and potentially, Robbie herself, so it's moving ahead.
Just because YOU don't know where Matt Reeve's Batman movie fits in here doesn't mean that Matt Reeves and WB don't know.
There are already several versions of The Joker. The world spins on.
I can't really argue how Batman, Nightwing and Batgirl movies being developed in tandem doesn't make sense and keep a straight face.
I guess that rather than wait and see how it all fits together, some of you have chosen to make assumption after assumption about it. Carry on.