Warning: Spoilers below for Fast & Furious 9.
Following his very minor role in Furious 7, Mr. Nobody is one of the major markers of the evolution of the Fast Saga from its street racing roots to Dominic Toretto and his crew being an on-call automotive special ops team who thumb their noses at the laws of physics. As a shadowy string-puller with a sardonic sense of humor, Mr. Nobody is now a significant player to the series, and one who shouldn't be left by the wayside.
Mr. Nobody is seen briefly in a video early in the film, with the news that he'd successfully captured Charlize Theron's Cipher, only for his plane to crash in Montecito. Mr. Nobody is also seen later in the film during flashbacks to the believed death of Sung Kang's Han, establishing that Mr. Nobody helped Han fake his death in the timeline overlap of Fast and Furious: Tokyo Drift and Furious 7. By doing this, Mr. Nobody better enabled Han to covertly protect the Ares device and Elle, played by Anna Sawai, after recruiting Han into his service.
No confirmation about Mr. Nobody's survival or death is ever given in the present tense of the film, but it would be a big mistake to kill him off so unceremoniously — and, with the Fast Saga heading into a two-part finale, really even at all. With the Fast & Furious series now more resembling a superheroic, ensemble version of the James Bond franchise, Mr. Nobody has been the man to call Dom's family up for the wilder missions they begun embarking on. In his own way, despite boarding the series relavtively late in the game, Mr. Nobody has a lot more to do with what the franchise is now than he might seem to. For the series to end well with Fast & Furious 10 and 11, Mr. Nobody needs to be involved.
Fast & Furious villain Hobbs, — who has a more hands-on approach — Russell's presence in the series presents a more behind-the-scenes counterpoint in Mr. Nobody. With his arrival, audiences immediately know that the next mission is afoot. Russell's tongue-in-cheek performance also lends a good amount of dry humor, not unlike Helen Mirren's portrayal of Shaw's mother "Queenie."
Russell's relatively minor appearance in F9 might've come down to scheduling issues on other projects, but it would be a big mistake for the Fast Saga to declare him dead now. With Cipher still on the run and the mystery of Hobbs and Shaw's Eteon organization still unresolved, Dom and his family are surely headed into a major showdown. After mostly keeping him on the bench in F9, the Fast & Furious series should make clear that Mr. Nobody's last rodeo still awaits him — giving the franchise the comprehensive, climactic ending that it deserves.
