An official Twitter account for Ubisoft's Watch Dogs game appears to suggest that an announcement about Watch Dogs 3 will be happening at E3 2019. Ubisoft will have a major presence at the games industry event, hosting its annual press conference, and Watch Dogs 3 could be one of the biggest announcements from the event.
Fans of Watch Dogs have come across an official Watch Dogs account with the handle @watchdogsgame_uk. The account was created in May 2019 and has the name "Watch Dogs UK" as well as a bio that says "Official Watch Dogs UK Account. Follow us for all the latest news, trailers & info!" The bio also features the @watchdogsgame_uk Instagram handle, which was used to promote Watch Dogs 2 when that was released in 2016. The Twitter account also has a verified symbol, so this is an official account for the series and not just from a hopeful fan.
The Watch Dogs UK Twitter account has an account profile symbol of the number two, taken from the Watch Dogs 2 logo, and its header image is from the Watch Dogs 2 box art. However, it would be very strange for Ubisoft to create a new account to start marketing a game which launched several years ago and has released all of its DLC. Ubisoft has probably registered the Twitter account ahead of a big Watch Dogs 3 announcement at E3 2019.
There have been many rumors about Watch Dogs 3, with one of the most popular suggestions being that Watch Dogs 3 will be set in London, UK. The leak said that the game would be released this year and would offer more hacking gameplay. So, it seems right that Watch Dogs 3's announcement has partially been leaked by fans doing some cyber sleuthing. If the game is set in London, then this is probably the reason that Ubisoft has created a UK Twitter account for the series, with many other Ubisoft franchises also having regional accounts like this.
As well as rumors and leaks, there have been teases through official Ubisoft accounts too. The Ubisoft Club app also appeared to confirm Watch Dogs 3 is in development, with the app's assistant talking about development builds and the talented development team behind the game.
A Watch Dogs trademark filing also appeared to suggest that Ubisoft wants to bring Watch Dogs 3 to the PS5 and the next Xbox. That hasn't been confirmed, but movements with the series trademark is another big suggestion that Ubisoft is doing something with the series. Whether or not that "something" is Watch Dogs 3 remains to be seen
Watch Dogs 3 is rumored to be in development for unspecified platforms.
Source: Twitter - Watch Dogs UK