Yes, the SNL alum and star / writer of Bridesmaids is in talks to become a DC Extended Universe villain.
Deadline reports that Wiig was high on director Patty Jenkins' list to play the evil Cheetah, and that she's currently in talks with the studio to see if the role is for her. It's not yet precisely known which iteration of Cheetah that Wiig's character could be playing, but whatever it is, it's a huge departure from her work and career up until this point.
The closest film that Wiig has in her filmography that'd be similar to Wonder Woman is either Ridley Scott's big-budget adaptation of The Martian, but that role was pretty much set in an office and featured her talking.
Evidently, if Wiig goes for the role, she's going to have train up on fighting and stunt work for the role, as Cheetah is described as having superhuman strength, speed and looking like a cheetah. Deadline's report also states that the film will be set in the '80s during the Cold War, so our guess is her character is going to be inspired by... the musical Cats? Paul Schrader's Cat People? Cheetara from Thundercats?
Who knows. Wonder Woman 2 is slated for November 1st, 2019.