The hiring went off like a sonic boom in Hollywood, reverberating to the highest levels of rival studios. “Awards Landscape Rocked as Netflix Poaches Leading Strategist,” the Hollywood Reporter headline read. Netflix had aided its own awards operation while dealing a blow to competitors by taking a top campaigner off the market.

And now the costly Oscar push that Ms. Taback has orchestrated for “Roma” is starting to look historic. Mr. Cuarón’s film, shot in Spanish and Mixtec and deemed a masterpiece by many critics, heads into the 91st Academy Awards next Sunday as a strong contender to win the Oscar for best picture. If Netflix notches its first such triumph, “the game changes forever,” said Marty Kaplan, the Norman Lear professor of entertainment, media and society at the University of Southern California.

If a film primarily distributed online wins, the debate in Hollywood about what constitutes cinema is over. It would strike a blow to the big multiplex chains, which have refused to show “Roma” because Netflix offered them an exclusive play period of only three weeks; three months is the norm. As far as box office figures, Netflix has said the film has appeared in about 250 theaters in the United States since it was released on Nov. 21, but it refuses to disclose ticket sales. A win by “Roma” could embolden old-line studios like Universal and Warner Bros. to shorten their own theatrical “windows.”

Winning would also make it easier for Netflix to compete with traditional studios for top filmmakers. (Its lone Oscar for a feature-length film to date has been best documentary, in 2018.) Even victories in lesser categories — “Roma” has 10 nominations in total and “The Ballad of Buster Scruggs” earned three more — would buoy the Netflix brand, giving the company a glow of excellence and helping it defend against a coming onslaught of competitors. Disney, WarnerMedia and Apple are all introducing megawatt streaming services this year.

Ms. Taback declined to comment for this article. Strategists like Ms. Taback try to avoid the media spotlight, especially before the Oscars, contending that they don’t want to take attention away from the films. Another reason, of course, is that no studio wants to look like it is trying to manipulate voters.