Let me guess, they wanted Sue Storm to be the one who defeats the Silver Surfer but they didn't want her to fight a male villain since that would make it look like the studio supports gender equality, so they replaced Silver Surfer with a female herald.
Let me guess, they wanted Sue Storm to be the one who defeats the Silver Surfer but they didn't want her to fight a male villain since that would make it look like the studio supports gender equality, so they replaced Silver Surfer with a female herald.