i'm surprised Warner Brothers doesn't have a way to protect the property, but the story (on comicbookresources) seems to say the producers aren't worried, they have a team of lawyers protecting them and they also said they're working on Marvel properties and Superman.
Years ago, back when porn had to be bought downtown and videos were only shown at theaters, I had some family members who ran some stores and therefore I had access to a lot of stuff of that nature. I remember one magazine I found laying around that had a pretty clear Superman/ Wonder Woman parody, but the publishers were verrrry careful not to have any costume or trademarked images appear in the book. Guess times change...