A couple of things to note
1. Themyscira has actually been identified in the DCTVU (Legends of Tomorrow) and the Amazons along with it ... I wouldn't be shocked to see more appearances of Helen of Troy and possibly some other Amazons attached to the show in the next season.
2. There has been at least 1 development attempt made for a WW TV show called "Amazon" (writer Allan Heinberg was attached to the project). WB/CW chose to not produce the pilot back in 2014.
I suspect WB is entertaining ideas around WW for a 2019/2020 pilot attempt ... it can take several years for a development project to produce a pilot so I am not surprised that only 1 year out from the film success that we don't yet have a viable TV project. But I also wouldn't expect the project to necessarily be about Diana, since they've already teased historical Amazons in LoT a spin off of that concept might be the most logical direction to go ... more of a focus like Krypton or Gotham is showing us.
And thank the Gods that show was cancelled. That pilot episode looked absolutely horrible. This is why I am afraid for a Wonder Woman TV show. I'd rather not have a show than have something so mediocre.
You are thinking about the David E Kelley show that actually got a Pilot ... the one I'm referring to never even filmed a pilot, it was just in development and never got off the ground!