Business class flight from the U.S. to Italy cost several times less: What is the deal

Discounts for business class flights from several US cities to popular destinations in Italy have caused a stir in the US media.
Several carriers are offering discounted tickets from many U.S. hubs, and there are deals available from now through the summer of 2024. "You can visit Rome, Florence, Milan, and Venice, or choose less popular destinations like Bari or Catania for as little as $2,200," The Points Guy article says.
What's involved
Airlines: Delta Air Lines, American Airlines, United Airlines, Air France and KLM
Routes: from Austin, Boston, Chicago, Dallas, Miami, Newark, New York, San Francisco, Seattle, and Washington, D.C. to various cities in Italy
How to book: check Google Flights and then book directly with the airline
Travel dates: October 2023 - July 2024
Book by: as soon as possible
The cost for week-long trips during this period varies significantly, seemingly at random.
For example, one business class trip departing on October 22 from Newark, New Jersey to Milan, Italy costs $5661 roundtrip.
When booking with American Airlines next week (departing on October 29 and returning on November 4), the cost of the trip suddenly drops to USD 2766.
It is noted that these fares are valid until the summer of 2024, so tourists have time to think and choose the most attractive route for themselves.