Assassins Creed and Watchdogs are both titles published by the mega video game development company, Ubisoft.
Both games are also alike in the sense that they are open-world, free-running, stealth-based, and have characters protecting their face/ identity in some of the cleverest ways possible.
However, the fandom has not stopped there, drawing a parallel that both games might be set in the same universe.
That has been the speculation for quite a while now. However, in Assassins Creed: Origins, Ubisoft might have taken a small move to confirm the speculations of their fans.
Note: Spoilers for Assassins Creed: Origins may exist beyond this line.
In Assassins Creed IV: Black Flag, a certain Oliver Garneau (CEO of Abstergo Industries) features in supporting roles and then leaves the city for Chicago. In the first edition of Watch Dogs published (based in Chicago), this same character appears as an Easter egg.
Garneau is seen on a mission that makes him a kill target for Aiden Pearce. This goes on to strengthen the connection between the two games that fans have been seeing for a while now.
Afterall, Assassins Creed: Origins and Watch Dogs might be set in the same universe under the Ubisoft management.