In an interview with Parade Magazine, Weaver -- who portrayed musician Dana Barrett, Peter Venkman's love interest, in Ghostbusters and Ghostbusters II -- confirmed that she will return for Reitman's film, which has previously been described as a sequel to the original films and not a reboot or continuation of the previous 2016 reboot.
According to Parade, Weaver wouldn't reveal any details about the movie except to confirm that she will play Dana and not a new character. “It’s going to be crazy working with the guys again!” Weaver said.
EDIT - Upon reading the article, I'm not sure where the confirmation that Murray is actually for sure in this movie is? Guess we'll find out tomorrow during Ghostbusters Fan Fest.