The Last of Us Part 2 it could actually be arriving in the 2019.
The Youtube channel Playstation Music has published three new tracks of the title (including the new main theme we talked about in this news). In the video description, we can read: "Music from The Last of Us Part 2 (2019)"
Although not an official confirmation, the news could hope for the release of the title N by the end of next year.
At this point we just have to wait for an official confirmation from Sony, which for now has always been vague about the release date of the game, probably to avoid controversy in case of a possible postponement.