2009’s “The Incredible Hulk” film setup both The Leader and Abomination as villains in the Marvel Cinematic Universe, with neither heard from again since that film.
The movie itself remains something of a black sheep in the MCU with lead actor Ed Norton swapped out for Mark Ruffalo, and the only returning cast member being William Hurt’s General Ross in “Captain America: Civil War”.
Out doing “Thor Ragnarok” promotion, Marvel Studios President Kevin Feige was asked by Crave Online about the fate of the two baddies. He says he’s open to them returning but they haven’t figured out a way to do it:
“It is an embarrassment of riches of places we could go or characters we could reprise or bring back now that we’re… I think Ragnarok is our seventeenth MCU film. And you would be surprised how many… its come up. Its come up. Just finding the right place. And as I said, if you can’t do it right, don’t do it or do it later, and the notion of ‘Hey, I’m here too! Next!’ is not interesting to us. Abomination is in a prison somewhere too.'”
A comic book prelude for “The Avengers” reportedly revealed that The Leader was taken into custody. Short of a cameo in a prison, it’s unlikely we’ll see them again anytime in the near future.