In February 2024, World's Edge announced that was slated to be out at the end of 2024. In October of that year, however, the DLC was to an unspecified "future [[link]] date," and today the studio announced that "after serious consideration," it's been cancelled entirely.
"We apologize that we haven’t provided any updates to you since [[link]] our announcement of the DLC," the studio wrote on . "While considering
the inclusions for last year’s [New Year,
New Age] [[link]] show, we wanted to ensure that Age 3: DE players felt part of the franchise celebration as we know you have huge passion and love for the game. However, pushing to ensure that the game was included meant we announced content before it had been built, and we now feel that announcement was premature.
(Those are the flags of the Polish-Lithuanian Commonwealth and Denmark, by the way.)
The last expansion for Age of Empires 3: Definitive Edition, Knights of the Mediterranean, was released in May 2022, and with this promised new DLC cancelled it sounds like the game will be effectively settling into maintenance mode: World's Edge didn't say there will be no more DLC ever, but it did say it "will continue to maintain servers, rotate civs through the free trial version, and provide Customer Support for any issues you may encounter whilst playing." Given that Age of Empires 3: Definitive Edition is now five years old, I'd say it's a good bet that this is where the studio puts a pin in it.