Reaching out through the Ubisoft community forums, it's been confirmed the schedule epic mercenary events for Assassin's Creed Odyssey will be placed on hold for now, as the first two live events were unfortunately canceled on the eve of their scheduled release. The first two live events were slated to occur on October 18th and 30th.
The premise of these live events is that Ubisoft would insert epic level mercenaries into the game, with these time-trials offering the chance for players to earn epic gear for either main character Alexios or Kassandra. It appears when the prior events had gone live, only a portion of players were able to access the free content, essentially fragmenting a large part of the community from what should have been a universal event. Mercenaries usually appear at random in Assassin's Creed Odyssey whenever a player's bounty reaches a high enough level, with procedurally-generated tougher enemies trying to track down and kill the player.
As of the time of writing, Ubisoft has stated it will be holding off on these mercenary events likely until the end of the month. In return, the studio has offered a similar weekly epic ship event and put items from the Oikos of Olympians set on sale next week. For players who haven't gotten far enough in the game's story to access either of these, don't worry, it takes quite some time to beat the game.
While the first few attempts at a time-trial offering for Assassin's Creed Odyssey is disappointing, Ubisoft thankfully has a longer time window than they usually do to make things right. The company's CEO Yves Guillemot confirmed back in August there would be no new Assassin's Creed game in 2019, as the team will look to support the game with said live events, as well as more DLC expected until this coming Spring.
Assassin's Creed Odyssey is available now for PC, PlayStation 4, and Xbox One.