It’s D-Day for Barneys New York — and, potentially, the entire high fashion retail world.

On Thursday, a bankruptcy court judge in Poughkeepsie, N.Y., is expected to rule on the fate of the famed retailer. It’s a decision that could have repercussions far from the corner of 61st and Madison in Manhattan — and not just because Barneys’ flagship store may well disappear if Authentic Brands Group, which last week announced its bid had been accepted, is officially anointed the new owner.

Authentic Brands’ plan involves potentially untying the intellectual property of Barneys — its name and brands — from its assets. That means the Barneys name would be licensed to Saks Fifth Avenue and the retailer’s inventory would be handed over to B. Riley, the financial firm with a robust liquidation business. All of its stores could close.

If the $271 million bid from Authentic Brands and B. Riley is approved on Thursday, the result could be eye-popping liquidation sales of luxury goods like handbags and dresses at all seven Barneys locations, perhaps starting as soon as this weekend. That would put a surfeit of discounted merchandise in the major fashion markets of New York and Los Angeles just as the holiday shopping season arrives — and long before other stores and brands put similar goods on sale.

“It will affect everyone, even online; Net-a-Porter, Saks, Neiman Marcus,” said Robert Burke, founder of a luxury consultancy and former fashion director of Bergdorf Goodman. “It’s potential retail mayhem. The only other time we have seen a major liquidation outside of the regular sale season was after 9/11, when no one was shopping and people panicked. It was really a disaster, because the customer never really forgets. And trying to retrain them can take years.”

Whether that comes to pass depends on any selection of an alternate bidder, and the possibility that new bidders or information cause the judge to wait to make a decision.

The potential rival to Authentic Brands who has been most public about his intentions is Sam Ben-Avraham, the retail and trade show entrepreneur. He assembled a consortium of investors to offer an alternative to Authentic Brands’ plan. With a nostalgia-driven “Save Barneys” campaign and a plan to maintain the flagship stores — and jobs — in New York and Beverly Hills, the investor in Kith and creator of a number of trade shows has been trying to position himself as the creative and entrepreneurial alternative to Jamie Salter, the founder and chief executive of Authentic Brands. He had not submitted a qualified bid for Barneys as of Wednesday.

Indeed, the Barneys drama increasingly seems like the tale of two men: on the one hand, the financial engineer, on the other, the merchant-impresario. (This week, David Jackson of the investment firm Solitaire Partners and former chief executive of Istithmar World, the Dubai-based group that owned Barneys from 2007 to 2012, said he was also planning to bid; his backers include the Saudi company Arabian Oud.)

Online and through press interviews, Mr. Ben-Avraham, 53, has cast Mr. Salter, 56, and Authentic Brands as villains looking to demolish Barneys as a cultural institution. In a petition online, Mr. Ben-Avraham said that turning Barneys into an intellectual property license operation would vanquish the store’s “unique identity, its point of view, its cutting edge agenda.”

The criticism has put a spotlight on Authentic Brands, which Mr. Salter founded in 2010, and its practice of buying the intellectual property of flailing or bankrupt brands. After a purchase, Authentic’s goal is to strike licensing deals with other companies that may want to use the brand name in new products, international collections and elsewhere. That translates to licensing fees and royalty payments for Authentic, which is typically removed from issues tied to stores, employees and inventory.

The first time Mr. Ben-Avraham walked into Barney’s was in 1992.

“It became my temple,” said Mr. Ben-Avraham, who immigrated to the United States from Israel in 1989. It also became, he said, the inspiration for his career: one focused on the curation of cool and the construction of communities around that.

In 2011, after several successful ventures including cofounding a multibrand men’s wear store and starting a popular trade show, Mr. Ben-Avraham invested in the nascent sneaker line Kith. It later grew into a full-fledged clothing collection shown at New York Fashion Week, a retail destination and lodestar of the streetwear revolution. There have been collaborations with LeBron James, Versace and Coca-Cola and lines outside its stores for releases of limited-edition merchandise.

Mr. Ben-Avraham has started and co-founded several trade shows focused on different types of apparel. They go beyond typical brand stalls and feature music and events — the sort of live experiences that Mr. Ben-Avraham was presumably talking about when he said, apropos of his plan for Barneys, “our specialty is creating environments people want to be part of.”

“Sam really is a merchant,” said Mr. Burke, albeit one who goes to Burning Man and works out of a SoHo loft. “He and his team are not corporate, not bankers, not strategists.”

Still, there are those who find his strategy — including a “Save Barneys” Instagram account filled with vintage ads and Barneys appearances in shows like “Sex and the City” — more romantic than realistic.

Authentic Brands says that its dozens of brands, which include Frederick’s of Hollywood, Nine West and the rights tied to celebrity names like Muhammad Ali, generate nearly $10 billion in annual retail sales. It also recently expanded into media, with the surprising acquisition of Sports Illustrated. (It licensed the publication’s operations to a separate company that cut jobs and sought to shift coverage to a network of bloggers.) The company, which is private, does not disclose how much it receives in sales or income.

“Jamie is incredibly smart, incredibly aggressive, and he rarely loses,” said Gerald L. Storch, chief executive of Storch Advisors.

Mr. Salter is from Toronto, where he still lives. He is married and has four sons, all of whom work in different roles at Authentic Brands. He started his retail career in sporting goods sales and marketing in the 1980s.

Mr. Salter earned his reputation for resurrecting brands after cofounding Hilco Consumer in 2006 and serving as its chief executive. It was a division of the financial firm Hilco, which has a robust liquidation business.

Hilco Consumer aggressively bought up the intellectual property of brands like Sharper Image, Linens ‘n Things and Polaroid through bankruptcy proceedings. New products bearing the brand names, like Sharper Image garment steamers, started appearing at retailers and new websites were introduced.

Mr. Salter views himself as a brand licensing expert, according to a 2009 interview with The New York Times — one who had learned how to receive royalties for merchandise while bypassing costs like store staff and rent. The strategy has thrived in the churning retail landscape of the past 15 years.

While Mr. Salter has his critics, he also has friends in the fashion industry, including Tommy Hilfiger. Mr. Hilfiger praised the executive’s “magic” touch with brands at a conference last year, saying that when Mr. Salter bought something, “the brand basically explodes.”

“He licenses it to many different categories, he doesn’t own any inventory — he’s like the Uber of the brand business today,” Mr. Hilfiger said during a panel discussion, seated next to Mr. Salter.

One of Authentic Brands’ earliest coups was the acquisition of exclusive rights tied to Marilyn Monroe, whose likeness drew the interest of everyone from Dolce & Gabbana to Walmart. In 2013, Mr. Salter, as part of a long-running lawsuit around use of the starlet’s likeness, described his company’s success in growing Ms. Monroe’s brand while staying true to her “DNA” through its partnerships.

“What’s really good is Marilyn Monroe is looking down from somewhere seeing that her brand is being exploited properly, to what she wanted,” Mr. Salter said in a deposition transcript.

Whether everyone will be happy with his plans to exploit the Barneys brand is another question. “The silver lining is Saks,” Mr. Burke said. “I am sure they care,” about the potential dangers of liquidation, he said.

As for Barneys stores, even if Authentic Brands keeps some of them open, the inventory will be liquidated, leading to major discounts on luxury goods, according to a person familiar with the plan who was not authorized to speak publicly. Some of the retailer’s biggest unsecured creditors include the Row, Balenciaga, Yves Saint Laurent, Gucci and Prada.

Mr. Storch said a liquidation sale before the holidays “would definitely have an impact on the market,” even if it’s only short term.