Based on current information, I Know What You Did Last Summer (2025) does not appear to include or explicitly portray transsexual characters or explore related themes. The film's narrative focuses on a slasher storyline, with no identifiable transgender representation mentioned in any available details.

The movie does not contain any action or adventure elements.

The film features the return of an original female character, Julie James, who maintains her established gender. New characters are introduced, but they are original to this installment and not gender-swapped versions of existing canon characters.

The provided information indicates a diverse cast and new characters like Teddy, but does not specify that any canonically established legacy characters from previous installments are being portrayed by actors of a different race. The focus is on new ensemble members rather than race-swapped returning roles.