Johnson himself has a new trilogy on the way for the Star Wars universe, as do the writers of Game of Thrones.
But there is also constant speculation about films relating to older, legacy characters – most prominently Obi-Wan, but also Boba Fett and Jabba the Hutt.
Solo: A Star Wars Story – an origin story for Han Solo – is out this May.
Asked by Express.co.uk if he thinks the focus should be on the new stories, or if there is room for looking back, Johnson said: “I think, honestly, for me it’s less about ‘is it the new stuff, is it the old stuff’.
“It’s more about if a film-maker comes with a take on an old character that is alive and vibrant, and engages with the audience – that’s what it’s all about.
“Whether you’re using the old stuff or creating new stuff, it’s kind of incidental. Is there a fresh story to be told? Is there something where, if it’s an old character, it doesn’t feel like we’re recycling the past?
“So yeah, I’m excited to see what they could be.”
Johnson is currently promoting the DVD and Blu-ray release of Star Wars: The Last Jedi, which is out on April 9.
The movie had a hugely successful theatrical run late last year, becoming one of the highest-grossing films of all time.
Attention will now turn to Star Wars: Episode 9; back in the hands of JJ Abrams, who previously helmed The Force Awakens in 2015.
Mark Hamill recently hinted that his Luke Skywalker could, in fact, return – depending on Abrams’ outlook.
Star Wars: The Last Jedi is out on Blu-ray and DVD on April 9.