I think theres a decent chance for another year. However I also think if ubi starts dedicating more resources to For Honor this game could make one of the biggest comebacks the gaming community has ever seen. If that is the case first and foremost rework this horrible ****ing engine on console and get all of us up to or around 60fps.
I think there will be a year 4. After all, we need one more assassin and one more hybrid added to the Wu Lin. That adds at least two seasons to the game. Plus, they confirmed they are developing new armor "soon". Just those two things really excite me.
What I would like to see the next seasons bring is mostly new armor and some faster executions. We don't get many quick ones now-a-days (although good creativity, Ubi!)