With Disney and Fox Studios voting on the merger this Friday, new batch of rumors has hit the net claiming the X-Men movies are done for, but also that certain Fox-owned Marvel characters are already in development for the MCU including Silver Surfer and Galactus.
Regarding Silver Surfer and Galactus in the MCU, a Fox Studios employee is claiming Marvel Studios has plans for certain Fox characters "unofficially in early development," which includes the two cosmic characters.
It's further speculated Silver Surfer and Galactus are probably not planned for The Avengers 4 (though Silver Surfer was rumored for Infinity War at one time).
The rumor may actually have some merit as way back in 2012 it was first reported by the Hollywood trade sites that Marvel Studios and Disney were trying to acquire the rights to the Silver Surfer and Galactus in exchange for an extension on the rights to Daredevil, which Fox Studios had at the time.
According to the report, Fox needed to get a new Daredevil movie underway by October of that year, so the ball was in their court. Obviously we know that didn't happen as the Daredevil rights reverted back to Marvel and the Netflix series was created, which meant Fox kept the rights to Silver Surfer and Galactus (2015 Fantastic Four movie was made to keep the FF character rights). I did theorize at the time that Marvel wanted use of the characters for an Infinity Gauntlet storyline in their films.
A second rumor that came about in 2012 offered that Marvel Studios actually wanted both of the characters for James Gunn's Guardians of the Galaxy film, with the rumor hitting about a month after Gunn was first said to be on board.
No details are known if the plans were for Gunn's version of Guardians that would have made use of the characters or science-fiction writer Nicole Perlman's first script, which Gunn rewrote (or both).
Regarding the Silver Surfer Infinity War rumor, an actor's IMDb page was updated with the listing, but eventually changed.
As the Russo brothers filmed both Infinity War and the sequel at the same time, could Silver Surfer really be for Avengers 4? Wound't it be wild if both Silver Surfer and Galactus appeared at the end of Avengers 4 attempting to devour the Earth, which led into the first ever MCU Fantastic Four movie (adapting "The Coming Of Galactus")? That would give the MCU Fantastic Four movie a much needed boost as it would get teased in what could be the biggest movie ever to be made.
Another possibility, and one that is my personal favorite, is that the MCU would adapt the epic Annihilation storyline that introduces Richard Rider Nova as an A-lister. Marvel Comics actually published four series, which led to the main Annihilation event series, with Silver Surfer being one of the books. A fourth possibility could be a flick based on Thanos Imperative, which at one time the Guardians of the Galaxy movie was rumored to adapt and would be a way to bring back Josh Brolin and the Great Titan to the MCU.
Joe Russo did recently offer that he is a big fan of the comic books and wants to keep the tone of the characters similar, but at the same time not to expect a straight adaptation as to keep the material fresh; so what exactly happens with the Silver Surfer and Galactus in the MCU remains to be seen.