The team is busy working on "some issues" that needed addressing.
It's not just Star Wars fans that have a reason to celebrate on May the 4, people playing Watch Dogs: Legion will have a pretty good time as well. The official Twitter account of the game has now explained that the promised Title Update 4.0 that were supposed to be released late April is now coming on May 4 instead, and they explain why:
"Our team is hard at work finishing up the next Title Update, 4.0, which was scheduled to go out in late April. While working on the different pieces of content, we encountered some issues that we need to address before deploying the update. We want the quality of this update to be in the best shape it can be. As such, we've made the decision to push the release date to May 4 to ensure a great launch.
This will allow us to continue our work on fixes for bugs that have been reported by our players via our Watch Dogs: Legion Bug Reporter, as TU 4.0 will also include more game improvements. We are really excited about you playing our upcoming content on Watch Dogs: Legion, and seeing all your reactions to our roadmap has been fantastic. Thanks for your ongoing support and passion.