A rumor circulating the internet this weekend says that the DC Extended Universe (DCEU) could be introducing Supergirl in their untitled Superman sequel which currently does not have a release date.
The rumor was first posted anonymously on 4chan.org this past Monday. Whether there is any truth or not remains to be determined. It’s likely all speculation but with the success of Wonder Woman, DC is probably looking at all of their books to get more female characters in leading roles on the big screen.
The sequel to Man of Steel has been developing in secret. Geoff Johns and Zack Snyder finished writing a story for the film back in November. Multiple writers were approached to turn into a screenplay including the writers from Watchmen and the 300 movie series. Brainiac will be the villain and Supergirl will be introduced to the DCEU.
The same person also suggested that Killer Frost, who is a character on The Flash series, will be in the sequel to Suicide Squad.
The DCEU and DCTV universe are not in the same shared universe. For someone who watches Grant Gustin play Barry Allen on The Flash, it will not be the same seeing Ezra Miller as the speedster. For what it’s worth, they have been having issues with finding a director. Imagine getting an origin story on screen just a few short years after watching it play out on both Arrow and The Flash.
Melissa Benoist is doing a fine job on Supergirl as Kara Danvers/Kara Zor-El. Just as with Gustin’s Barry Allen, fans are so attached to the TV series that seeing different characters on the big screen would be doing a disservice to the TV universe. It was already confirmed by Arrow’s Willa Holland that they wouldn’t let Arrow use someone as a villain because of an expected appearance as a villain in a film. In fact, the series killed off both Amanda Waller and Deadshot. The same thing happened on Gotham with a character playing someone who was supposed to become the Joker.