The first film was set in WWI and the next Wonder Woman film is set in 1984, so don't expect a "sequel" says producer Charles Roven, which makes sense as there is an obvious big time jump.
“[Patty Jenkins] was just determined that this movie should be the next iteration of Wonder Woman but not a sequel,” Roven tells Vulture. “And she’s definitely delivering on that. It’s a completely different time frame and you’ll get a sense of what Diana-slash–Wonder Woman had been doing in the intervening years. But it’s a completely different story that we’re telling. Even though it’ll have a lot of the same emotional things, a lot of humor, a lot of brave action. Tugs at the heart strings as well. It’s a stand-alone film in the same way that Indiana Jones or Bond films are, instead of one continuous story that requires many installments.”
Roven also revealed that Jenkins is about 25% done with post-production.
Wonder Woman 1984 has a June 5, 2020 release starring Gal Gadot as the titular character, Chris Pine is back as Steve Trevor, Kristen Wiig plays the supervillain Cheetah, with Pedro Pascal in a mystery role.