Meaning.. another series of movies related to JRR Tolkien's writings?
I sure hope so! They could do a prequel thing and make "The Hobbit". And all other books that Christopher Tolkien edited.
I personally would love to see Silmarillion on film.
😄
Fanfic?.. Doubt that. With all the legal matters goin on with Tolkien Enterprises? 😕
Tolkien did a vast amount of background for Middle-Earth- in fact, he did the background first and then wrote LOTR afterwards- some of which can be explored in works like the Silmarillon, and some of his musings seen in Unfinished Tales.
On the whole, though, no. Whilst Tolkien was keen on creating a whole new mythology, the stuff we have is all there is and no-one else has ever been allowed to add to it.