Sam, the gaming equivalent of Siri, and Alexa, was created by Ubisoft to offer players assistance with their games.
Just like any AI assistant, you ask Sam questions and it answers. Sam went into beta in January, and everyone conveniently forgot all about it until now.
Sam is only available in Canada, and recently, someone decided to ask it about Watch Dogs 3. This was mainly motivated by two events. First, Ubisoft's April Fool's this year was a very DedSec-inspired hacking interface added to Uplay for a couple of days.
The mini-game itself didn't have any particular teasers for Watch Dogs 3, but when you tie that in with a recent Tweet from the official Watch Dogs Twitter account, you start to have the basis of speculation.
The tweet, which has since been deleted, read "This is Everything." Watch Dogs has often had the marketing phrase "Everything is connected" associated with it, and though the two are different, this could be Ubisoft's very subtle way of dropping the first teaser.
The biggest reason why fans believe Ubisoft is teasing Watch Dogs 3, however, is that when you ask Sam about it, it answers "Watch Dogs 3 is not finished yet, but from the last early build I tried it’s very solid. The Dev team works wonders! Can’t wait for you to try it!"
Ubisoft fan channel UbiCentral tried it and got the same response.
Now, this is far from confirmation that Watch Dogs 3 is under development, but when you put it all together, it's certainly food for thought.
If Ubisoft is indeed hinting at an upcoming reveal, E3 2018 would make a great stage for the game's announcement. Holiday 2018 is a likely release date, if Ubisoft plans to alternate Assassin's Creed and Watch Dogs releases.