I suspect they are saving Norrin Radd for the sequel. I think people sort of want to see 3 folks in a Fantastic Four movie. Norrin Radd,Dr, Doom and Galactus. If they make 3 Fantastic Four movies they will likely want to spread these people out so at least one of them will be in each movie. Also Norrin Radd strikes me as a character they are going to be really careful with because he could be someone, if he works out who gets a movie of his own. In the meantime Garner's character gives you a little Silver Surfer action and sort of teases the future arrival of Norrin Radd. I would also not be shocked if he or his role in Fantastic Four is teased in a post credit scene. It will likely be him or Doom. I do wonder if Garner's character and Radd will be dating like I believe was the case in the comics.