In a June 1, 2016 Blumhouse.com "Shockwaves" podcast, screenwriter Mike Flanagan wrote that this new iteration and re-imagination of the original film would not have any connection to the Lois Duncan novel (the antagonist being a central character) nor the 1997 feature (the fisherman Ben Willis and 4 primary protagonists Julie James, Helen Shivers, Barry Cox, and Ray Bronson). Further, the new direction and scope of the film necessitated an estimated budget of $15-20 million. This planned remake eventually fell through, and instead, a TV series reboot was released simply called I Know What You Did Last Summer (2021) with Madison Iseman and Brianne Tju. The series was canceled due to low ratings and negative reviews, so a sequel to the original movie was confirmed instead in 2023, with Jennifer Love Hewitt and Freddie Prinze Jr. returning.
Karen Gillan was rumored for a role in the film back when Mike Flanagan was still attached to the project.
Yan-Kay Crystal Lowe, Nina Dobrev, Kristen Bell, Ashley Tisdale, and Mercedes McNab were all in talks to play unspecified roles in the film back when it was in development as a remake with Mike Flanagan.