2013: The Last of Us
2014: The Last of Us: Left Behind (standalone DLC)
2016: Uncharted 4: A Thief's End
2017: Uncharted: The Lost Legacy (standalone DLC)
"Uncharted: The Lost Legacy is a new adventure in the series starring Chloe Frazer. The game will be offered as both a stand-alone title and as part of the Uncharted 4 season pass---though you only have until December 13th to purchase the season pass or the Digital Deluxe version of the game which comes with the season pass."
2020: The Last of Us - Part II
2021: Standalone The Last of Us multiplayer game (not part of The Last of Us - Part II)
You heard it here first.
Personally I wouldn't mind this, as we, the players, would get the most ambitious single player campaign to date, as well as what will probably Naughty Dog's most ambitious multiplayer. Giving the multiplayer 1-1½ years more development time will certainly benefit all parties.