With the more recent movies featuring very strong female protagonists, the trend of bringing in more female leads is pretty much expected. Between Ms. Marvel (Captain Marvel) and the future Wonder Woman movie, along side DC bringing in Supergirl and and giving Hawkgirl their own TV shows. But, DC tried this back then with Birds of Prey, while they were still experimenting with bringing superhero shows in the live action motif, alongside the success of Smallville at the time.
I do have high hopes for the Wonder Woman movie, and while I still have reservations on the actress, I think she could pull it off. But the first movie is suppose to be set in the 1920s and they are going to explore some common themes pertaining to women, especially during that time.