Pedro Pascal as Reed Richards, via @DiscussingFilm months early — confirmed
Reported on Nov 15, 2023; Marvel announced the cast on Feb 14, 2024.
Leaked on 15 November 2023

On Nov 15, 2023, @DiscussingFilm posted that Pedro Pascal would star as Reed Richards in Fantastic Four, citing Deadline.
Deadline’s report published that day. Marvel announced the cast on Feb 14, 2024, with Pascal, Vanessa Kirby and Joseph Quinn, per Variety and The Washington Post.
Confirmed.