During an interview with GameInformer, Naughty Dog explained the reasons behind Uncharted 4's The Lost Legacy expansion being standalone, and writer Josh Scherr said it was partly to do with creating something away from the main story.
"We had the unique opportunity to do something that was truly stand-alone, unlike Left Behind which was like the missing chunk of the story in The Last of Us," Scherr said. "This is something we can do completely independently while still in the same universe with the same characters, and exploring new relationships with them."
"We tried to keep it small," game director Kurt Margenau added. "As we started coming up with story ideas, it just became clear that with new characters and in this genre of Uncharted, it has to be big. With the gameplay stuff we wanted to explore, it felt like it needed more room to breathe."
Does this sound promising, or would you prefer something like Left Behind instead?