He has? I hadn't noticed. He sounded flattered (though perhaps a bit unnerved) by the fan reception of his character when people asked him about it. But I can see why he would want to break away from Loki fever - ignoring the fanbase, some actors probably don't want to be type-cast in that sort of niche for the rest of their lives. Especially this early in their careers. And it'll be nice to see him return to comedy for a bit; it can't be easy to play tragic character after tragic character after tragic movie character before you find yourself stuck in a permanent case of the slums. But Hook is a pretty big deviation from his norm. The writing for the Tinkerbell movies isn't exactly Shakespeare, and while Hiddleston has played lighthearted characters and maybe a goofball here and there, Hook is a very special sort of goofball. He can be cutthroat, cruel, and diabolical, but he also runs crying to his fuddy-duddy old first mate when he hears a ticking clock. I have no doubt Hiddleston can pull off the cutthroat, cruel, and diabolical aspects, but it'll be . . . interesting to hear a guy who's usually so dang quiet wail like a giant man-baby.
As for his role in the Muppets sequel, I thought that was a combination of Lifetime Bucket List and Celebrity Status Bucket List. Y'know, a list of iconic roles to play, people to work with, stuff to do to mark ones acting career as a true success to be remembered in all the history/record books. He's doing pretty well so far.
Create an iconic character in a multimillion dollar franchise - check
Work with Steven Spielberg - check
Amass a faithful fanbase who value you for who you are and what you can do rather than embarrassing publicity stunts - check
Work with iconic characters and performers from Jim Henson's Creature Workshop - check (and about to be double check)
Work off various critically acclaimed movie and theater icons - checks all over the place
Play an animated character for Disney - almost check
Besides, who's gonna say "no" when the MUPPETS are asking you to be in their movie?