In the lead-up to Quentin Tarantino’s “Once Upon a Time … in Hollywood,” there was some fretting about how a director known for grindhouse exploitation might handle the summer of 1969, when the Manson murders capped a period of social upheaval. While Tarantino does get around to what happened on Cielo Drive on the fateful night of Aug. 9 — albeit with a twist — the film turned out to be a sweeter, more nostalgic treatment of the end of an era, capturing a moment where everything was about to change forever.

Now 50 years later, it’s only fitting that “Once Upon a Time … in Hollywood” is part of a field of contenders for best picture, because it feels like a time when Hollywood itself is undergoing a massive transformation.

2019 will be remembered as the year that Disney acquired 20th Century Fox. And when the introduction of Disney Plus, Apple Plus, and other streaming services shifted the polarities of the business, requiring such existing streamers as Netflix, Amazon Prime and Hulu to amplify their efforts in this competitive arena. The questions of when and how people watch movies is more wide open than ever, and awards contenders have the power to legitimize newcomers or affirm the lasting influence of the studio system.

That sense of instability and uncertainty has been reflected in the field of potential nominees, many of which organize around a theme of disruption. There are aesthetic disruptions, as in the treatment of history in “Once Upon a Time … in Hollywood” and Martin Scorsese’s “The Irishman,” or the Molotov cocktail thrown by Todd Phillips’ “Joker.”

And there are breaks in marketing and distribution channels, too, including the renewed incursion of Netflix the year after “Roma,” the tricky proposition of Taika Waititi’s Nazi satire “Jojo Rabbit,” and an insurgent indie campaign to bring Bong Joon-ho’s Cannes-winning oddity “Parasite” to the podium.

The films that get nominated, especially the one that ultimately comes out on top, will say something about the state of things in Hollywood — because for now, it feels very up in the air.

One producer who’s assured to have a great year is David Heyman, an Englishman who’s best known for shepherding the “Harry Potter” series from book to screen over a decade-long stretch. He reunited with Alfonso Cuarón, his director on “Harry Potter and the Prisoner of Azkaban,” for the 2013 hit “Gravity.” In 2019, Heyman straddled the studio-streamer divide by producing “Once Upon a Time … in Hollywood” for Sony and Noah Baumbach’s “Marriage Story” for Netflix, both critical favorites that are near certain to make him a double nominee for best picture.

Asked about Tarantino’s liberties with history, which track with the violent fantasies of “Inglourious Basterds” and “Django Unchained,” Heyman notes the character of Sharon Tate (Margot Robbie), who symbolized his impulse to revise the record.

“She is largely remembered through popular culture as a victim of the Manson murders,” says Heyman. “And for Quentin, he wants to show her as a figure of innocence and purity, because when he did his research — and he researched a lot — she came across as a really lovely person and also an actress of great talent.

“I think that Quentin is a great lover of movies and of TV and popular music,” he says. “And in some ways there’s a part of that rewriting or reworking that is a reflection of that love, if only life could be in some ways like the movies.”

That “print the legend” mentality also affects Scorsese’s “The Irishman,” another sprawling epic by a veteran filmmaker who’s reflecting ruefully on getting older and looking at history through the rearview mirror. For Netflix, it’s a massive swing for the fences, a reported $159 million production that’s nearly 3½ hours long, reunites the “GoodFellas” and “Casino” team of Robert De Niro and Joe Pesci, and brings another icon, Al Pacino, into the ensemble as Jimmy Hoffa. Based on Charles Brandt’s book “I Heard You Paint Houses,” about the exploits of mob hitman Frank Sheeran (De Niro), who claimed to have assassinated Hoffa, the film digs controversially into one of the great unsolved mysteries.

The year after an expensive campaign for Cuarón’s “Roma” fell short, Netflix is coming back with a more formidable slate that includes “The Irishman” and “Marriage Story” as well as “Dolemite Is My Name” and “The Two Popes,” which should at least make some noise in the acting categories.

With the acclaimed political drama “The Report” coming later in the year from Amazon, it could finally be the year that streaming services eclipse their studio counterparts (as happened at the Emmys), despite persistent questions, with Netflix specifically, about what that means for the theatrical experience.

The combination of a theatrical window and a premiere on the service before the end of the year will all but guarantee more eyes on its films than others, but “Marriage Story” also represents the type of small story that studios are increasingly reluctant to support. It’s a modern “Kramer vs. Kramer,” but without a natural home in the system.

“I love making adaptations like ‘Harry Potter,’ which was a big quote-unquote ‘franchise,’ though I never viewed it as such,” Heyman says. “But the challenge with films like ‘Marriage Story’ is that with the emphasis on these big-branded films, original content without the provenance of IP is harder to get made and harder to show.”

Yet IP can be radical, too. With “Joker,” Phillips and Warner Bros. have found a way to take the most popular super villain in comics and engage in provocative social critique, like “Taxi Driver” in face paint. And like “Taxi Driver,” which won the Palme D’Or at Cannes Film Festival en route to a hugely controversial release and an eventual best picture nomination, “Joker” is riding its significant cultural impact (and huge box office) and major festival award, the Golden Lion in Venice, to serious awards consideration. Along with Marvel’s “Avengers: Endgame,” it could further legitimize comic-book movies as a genre for substantive storytelling.

Fox Searchlight’s “Jojo Rabbit” is also taking a rockier path to the podium, but not one without precedent. For years, the People’s Choice Award at the Toronto Film Festival has been a reliable bellwether for Oscar contenders, including best picture winners “Slumdog Millionaire,” “The King’s Speech,” “12 Years a Slave,” and last year’s “Green Book.” But a truer model might be Roberto Benigni’s “Life Is Beautiful,” which won the prize in 1998 and had a wildly successful Oscar run, despite fierce debate over its seriocomic treatment of the Holocaust. Waititi’s film about a German boy with an idiotic Adolf Hitler as his imaginary friend walks a similarly thin line, to the point where Fox Searchlight has promoted it as “an anti-hate satire.”

There are plenty of best picture contenders to come from various distributors, including Sony’s “A Beautiful Day in the Neighborhood” and “Little Women” or Fox’s “Ford v. Ferrari,” and such earlier releases as Focus’ “Downton Abbey” and A24’s “The Farewell” in contention. But an insurgent campaign is in the offing for Bong Joon-ho’s “Parasite,” a twisty psychological thriller about a family of scam artists that infiltrate the home of wealthy elites. Critics have been championing the film since it won the Palme d’Or in Cannes in May, and Neon believes it can disrupt a highly competitive field through months of festival buzz and activating “the Bong Hive.”

“The film has built a rather large presence on its own, combined with Bong’s incredible canon over the last 20 years,” says Tom Quinn, Neon’s co-founder and CEO. “Not to be overlooked, it’s officially the top-rated film [of 2019] on Rotten Tomatoes, standing above ‘The Irishman’ and a whole bunch of contenders this year.”

The one possible roadblock is that “Parasite” is a film best seen cold, lest any of its nested twists be revealed. The challenge for Neon is to entice audiences to see it without giving anything away. “That was Bong’s plea out of the gate before the film world-premiered in Cannes,” says Quinn. “It’s infectious. When was the last time you went to a theater and were truly surprised?”