https://www.gamespot.com/articles/assassins-creed-odyssey-was-nearly-finished-a-year/1100-6462239/

Assassin's Creed Odyssey follows just one year after Origins, echoing the annual sequels that are widely believed to have led to franchise fatigue before Ubisoft took a year off to tinker with the formula. That doesn't necessarily mean we should expect a resuming of annualized sequels, according to chief creative officer Serge Hascoet.

"What we did was we built two teams--one in Montreal and one in Quebec--and we wanted to give them enough time," Hascoet told Game Informer. "I played Assassin's Creed Odyssey last November, and it was nearly finished. For us it's not a question of annualization, it's more a question of quality. If the team has enough time to produce and polish something, if it's at the highest quality, I think people can enjoy an experience of 80 hours every year. It's possible, but I’m not saying we will have one every year. It's not the plan."