Death Stranding may be delayed if you can call it that as the game doesn't have a release date yet. Hideo Kojima confirmed it is behind schedule at the moment, but it is kind of unknown what this could mean for the horror courier simulator.
Death Stranding is a little bit behind schedule apparently since Kojima is looking to further test the game out and deliver a more polished product. His reasoning here is that Death Stranding is an open world game and as such, it requires additional testing.
Kojima added that delays in game development are a common occurrence and that Death Stranding's delay is just a slight push back . To be fair, neither Sony nor Kojima Productions revealed an official release date so a delay in development is not the end of the world, but his statements confirmed the existence of an internal release window.
Still, there was that Kojima Productions tweet stating Death Stranding would come out before the new Akira and Tokyo Olympics in 2020 meaning there is about 15 months left in that time window. This delay may be conflicting with those plans though, so the question of whether Death Stranding or Olympics will come first remains open.
PlayStation 5 has not been revealed yet and its release date is also unknown but fans are starting to expect Death Stranding to end up being a bridge between the current and the next generation of the console, the same way it happened with Metal Gear V.
Kojima talked to a Japanese newspaper in November 2018, revealing that Death Stranding is in the polishing phase which could mean that a late 2019 release is still on. On top of that, another interview with Famitsu mentioned that the game would come out at some point in 2019.
Sadly, none of the information is conclusive at the moment and E3 2019 will likely not yield any information since Death Stranding is a Sony exclusive. This year's E3 is also the first one Sony will not attend, whoops.